This article proposes and demonstrates a retrodirective array(RDA)for two-way wireless communication with automatic beam tracking.The proposed RDA is enabled by specifically designed chips made using a domestic comple...This article proposes and demonstrates a retrodirective array(RDA)for two-way wireless communication with automatic beam tracking.The proposed RDA is enabled by specifically designed chips made using a domestic complementary metal-oxide semiconductor(CMOS)process.The highly integrated CMOS chip includes a receiving(Rx)chain,a transmitting(Tx)chain,and a unique tracking phaselocked loop(PLL)for the crucial conjugated phase recovery in the RDA.This article also proposes a method to reduce the beam pointing error(BPE)in a conventional RDA.To validate the above ideas simply yet without loss of generality,a 2.4 GHz RDA is demonstrated through two-way communication links between the Rx and Tx chains,and an on-chip quadrature coupler is designed to achieve a nonretrodirective signal suppression of 23 dBc.The experimental results demonstrate that the proposed RDA,which incorporates domestically manufactured low-cost 0.18 lm CMOS chips,is capable of automatically tracking beams covering±40with a reduced BPE.Each CMOS chip in the RDA has a compact size of 4.62 mm^(2) and a low power consumption of 0.15 W.To the best of the authors’knowledge,this is the first research to demonstrate an RDA with a fully customized CMOS chip for wireless communication with automatic beam tracking。展开更多
The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In...The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In this study,we apply the TWCC method to improve the performance of reference-frame-independent quantum key distribution(RFI-QKD),and analyze the influence of the TWCC method on the performance of decoy-state RFI-QKD in both asymptotic and non-asymptotic cases.Our numerical simulation results show that the TWCC method is able to extend the maximal transmission distance from 175 km to 198 km and improve the tolerable bit error rate from 10.48%to 16.75%.At the same time,the performance of RFI-QKD in terms of the secret key rate and maximum transmission distance are still greatly improved when statistical fluctuations are considered.We conclude that RFI-QKD with the TWCC method is of practical interest.展开更多
The objective of this study was to experimentally evaluate children’s daily food memory and eating habits.The study found that the gender and school location had an impact on the nutritional condition of primary scho...The objective of this study was to experimentally evaluate children’s daily food memory and eating habits.The study found that the gender and school location had an impact on the nutritional condition of primary school students as well as the school food scheme.The investigations were based on three hypotheses and three research questions.In this study,the Eating Habits and Daily Dietary Recall Scale was the tool utilized to gather data(EPDDRS).Four experts—three from the department of vocational education and one lecturer in test and measurement evaluation—validated the instrument’s face.The dependability indices of EPDDRS were calculated using Cronbach’s Alpha.While delivering the instruments,the researcher used the direct administration and retrieval approach.58 instructors and a sample size of 1240 students were selected using a systematic random selection approach.The obtained data was examined using mean and standard deviation to address the research objectives,and the null hypotheses were tested using t-test statistics and Analysis of variance(ANOVA)at the 0.05 level of significance.The main conclusions of this study were that the school meal program had a favorable impact on the students’nutritional status.Also,a balanced ration of nutrient-dense meals that were suitably varied was supplied for the students via the school food program.Also,the findings revealed a substantial difference in the mean assessments of male and female students about their eating patterns.On the school meal program’s dietary recall list,students from high,middle,and low socioeconomic status differ significantly.Recommendations were given to the government,schools,and parents based on the study’s findings.The study’s shortcomings were discussed,and recommendations for more research were made.展开更多
In this paper,an intelligent reflecting surface(IRS)-and-unmanned aerial vehicle(UAV)-assisted two-way amplify-and-forward(AF)relay network in maritime Internet of Things(IoT)is proposed,where ship1(S1)and ship2(S2)ca...In this paper,an intelligent reflecting surface(IRS)-and-unmanned aerial vehicle(UAV)-assisted two-way amplify-and-forward(AF)relay network in maritime Internet of Things(IoT)is proposed,where ship1(S1)and ship2(S2)can be viewed as data collecting centers.To enhance the message exchange rate between S1 and S2,a problem of maximizing minimum rate is cast,where the variables,namely AF relay beamforming matrix and IRS phase shifts of two time slots,need to be optimized.To achieve a maximum rate,a low-complexity alternately iterative(AI)scheme based on zero forcing and successive convex approximation(LC-ZF-SCA)algorithm is presented.To obtain a significant rate enhancement,a high-performance AI method based on one step,semidefinite programming and penalty SCA(ONSSDP-PSCA)is proposed.Simulation results show that by the proposed LC-ZF-SCA and ONS-SDP-PSCA methods,the rate of the IRS-and-UAV-assisted AF relay network surpass those of with random phase and only AF relay networks.Moreover,ONS-SDP-PSCA perform better than LC-ZF-SCA in aspect of rate.展开更多
This paper investigates the security and reliability of information transmission within an underlay wiretap energy harvesting cognitive two-way relay network.In the network,energy-constrained secondary network(SN)node...This paper investigates the security and reliability of information transmission within an underlay wiretap energy harvesting cognitive two-way relay network.In the network,energy-constrained secondary network(SN)nodes harvest energy from radio frequency signals of a multi-antenna power beacon.Two SN sources exchange their messages via a SN decode-and-forward relay in the presence of a multiantenna eavesdropper by using a four-phase time division broadcast protocol,and the hardware impairments of SN nodes and eavesdropper are modeled.To alleviate eavesdropping attacks,the artificial noise is applied by SN nodes.The physical layer security performance of SN is analyzed and evaluated by the exact closed-form expressions of outage probability(OP),intercept probability(IP),and OP+IP over quasistatic Rayleigh fading channel.Additionally,due to the complexity of OP+IP expression,a self-adaptive chaotic quantum particle swarm optimization-based resource allocation algorithm is proposed to jointly optimize energy harvesting ratio and power allocation factor,which can achieve security-reliability tradeoff for SN.Extensive simulations demonstrate the correctness of theoretical analysis and the effectiveness of the proposed optimization algorithm.展开更多
Background: Cognitive impairment becomes more common with ageing and may benefit from intervention. In a Spanish speaking population, detection of cognitive impairment by a general practitioner in Primary Care can be ...Background: Cognitive impairment becomes more common with ageing and may benefit from intervention. In a Spanish speaking population, detection of cognitive impairment by a general practitioner in Primary Care can be a problem, as many of the standard tests target English speaking populations. The Memory Impairment Screen (MIS-A) is a validated test using English words to detect Alzheimer’s Disease (AD) and other dementias. We have modified this test to suit a Spanish speaking population and added a new component, delayed recall. We have called our new test the Memory Impairment Screen with Delayed Recall (MIS-D). Objectives: 1) To test a Spanish version of MIS-A and MIS-D. 2) To assess the discriminative validity of MIS-D as a screening tool for the amnestic variant of Mild Cognitive Impairment (aMCI) in a group of Spanish speaking people aged 65 years old and over. Methods: A case-control study of a cohort of 739 native Spanish speaking residents of Buenos Aires aged 65 years old and over, of whom 436 were healthy controls and 303 had a diagnosis of aMCI. Measurements: Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NVP) were estimated for MIS-D and MIS-A. Results: Normative values for MIS-A and MIS-D were obtained from the control population. Both age and education significantly affected these values (p < 0.0001). Control participants showed significant differences for both modalities, MIS-A and MIS-D. The cut-off for MIS-A should be 7.5 and for MIS-D, 5.5. Comparison between control population and aMCI population using ROC curve gave a result of 5.5 in MIS-D, with 97% specificity and 76% sensitivity. Conclusion: MIS-D was positively predictive of aMCI, with 97% specificity and 76% sensitivity in a sample of Spanish speaking patients aged 65 years old and over in Buenos Aires.展开更多
A 57-year-old woman underwent abdominal surgery with a subarachnoid block supplemented by “light” general endotracheal anesthesia consisting of a propofol infusion and a sub-MAC concentration of sevoflurane. The pre...A 57-year-old woman underwent abdominal surgery with a subarachnoid block supplemented by “light” general endotracheal anesthesia consisting of a propofol infusion and a sub-MAC concentration of sevoflurane. The previous case in the same operating room had involved a malignant hyperthermia-susceptible patient, and charcoal filters had been placed in the breathing circuit as a precautionary measure. Because it had not been used on the evening beforehand, the circuit with filters was left in situ with a strip of tape indicating that it was clean. The woman’s anesthesiologist assumed that these filters were heat and moisture exchanger filters in an unused circuit and therefore did not remove them. Subsequently, the patient had awareness with intraoperative recall. This case highlights the potential for inadvertent use of activated charcoal filters with potentially catastrophic results. Such unintended utilization of these products likely can be minimized by improved labeling techniques.展开更多
<strong>Objective</strong><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability a...<strong>Objective</strong><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of the International Physical Activity Questionnaire (IPAQ). </span><b><span style="font-family:Verdana;font-size:12px;">Methods</span></b></span><span style="font-family:Verdana;">:</span><span style="font-family:Verdana;"> IPAQ was evaluated for test-retest reliability within 6</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">-</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">8 days of its first administration. Criterion validity was tested comparing IPAQ data with those from an activity meter (Intelligent Device for Energy Expenditure and Activity, IDEEA). </span><b><span style="font-family:Verdana;font-size:12px;">Results</span></b><span style="font-family:Verdana;font-size:12px;">: The test-retest correlation (n = 71) for items of IPAQ ranged from r = 0.63 to r = 0.74 and w</span></span><span style="font-family:Verdana;">as </span><span style="font-family:Verdana;">r = 0.79 for the total weekly PA in MET*min per week. Average PA (in MET*min/week) measured with the IDEEA meter, decreased from normal (15</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">840), to 14</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">278 in overweight</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">(BMI</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">></span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">25-</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;"><</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">30) and further to 12</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">803 in obese subjects (>30. BMI). The weekly energy expenditure measured by IDEEA correlated significantly (r = 0</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">61,</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">r</span><sup><span style="font-family:Verdana;font-size:12px;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> = 0.38) with the IPAQ data, providing an objective criterion for validity of IPAQ. The mean values of weekly PA estimated from IPAQ (in MET*min/week) differed significantly in the high (15</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">690) vs. the low (11</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">398) activity groups but not between the moderate (12</span><span style="font-family:Verdana;">,</span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">056) compared to the low PA group. The IPAQ criteria used to categorize subjects as moderately active, erred by including too many low PA subjects. IDEEA measurements in sedentary subjects overestimated their energy expenditure. </span><b><span style="font-family:Verdana;font-size:12px;">Conclusions</span></b><span style="font-family:Verdana;font-size:12px;">: IPAQ can be reliably used to distinguish low and high PA groups and yields relatively low estimates (−</span></span><span style="font-family:Verdana;">18%) of weekly PA in these groups compared to those measured with the activity meter. Stricter criteria are needed to distinguish moderate from low PA groups. Overweight and obese subjects showed significantly lower levels of PA than normal BMI subjects.</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">IDEEA overestimates low levels of PA.</span>展开更多
BACKGROUND Radiation recall dermatitis has been defined as the "recalling" by skin of previous radiation exposure in response to the administration of certain response-inducing drugs. Although the phenomenon...BACKGROUND Radiation recall dermatitis has been defined as the "recalling" by skin of previous radiation exposure in response to the administration of certain response-inducing drugs. Although the phenomenon is relatively well known in the medical world,an exact cause has not been documented.CASE SUMMARY Here, we report the rare occurrence of radiation recall dermatitis after palliative radiotherapy for bone metastases in a metastatic melanoma patient treated with a combination of dabrafenib and trametinib.CONCLUSION We present a case of radiation recall dermatitis after completion of palliative radiotherapy while being treated with a combination of dabrafenib and trametinib. This is a very rare toxic event, and there is insufficient data to describe prevention strategies. Increased awareness and reporting of cases will help to better explain the association between targeted therapy and the radiation recall phenomenon.展开更多
Background:As sedentary behavior is a global health issue,there is a need for methods of self-reported sitting assessment.The accuracy and reliability of these methods should also be tested in various populations and ...Background:As sedentary behavior is a global health issue,there is a need for methods of self-reported sitting assessment.The accuracy and reliability of these methods should also be tested in various populations and different cultural contexts.This study examined the validity of longterm and short-term recall of occupational sitting time in Finnish and Chinese subgroups.Methods:Two cohort groups of office-based workers(58.6%female,age range 2267 years)participated:a Finnish group(FIN,n=34)and a Chinese group(CHI,n=36).Long-term(past 3-month sitting)and short-term(daily sitting assessed on 5 consecutive days)single-item measures were used to assess self-reported occupational sitting time.Values from each participant were compared to objectively measured occupational sitting time assessed via thigh-mounted accelerometers,with Spearman’s rho(r)used to assess validity and the Bland-Altman method used to evaluate agreement.Coefficients of variation depicted day-to-day variability of time spent on sitting at work.Results:In the total study sample,the results showed that both long-term and short-term recall correlated with accelerometer-derived sitting time(r=0.532,95%confidence intervals(CI):0.3360.684,p<0.001;r=0.533,95%CI:0.4490.607,p<0.001,respectively).Compared to objectively measured sitting time,self-reported occupational sitting time was 2.4%(95%CI:0.5%to 5.3%,p=0.091)and 2.2%(95%CI:0.7%3.6%,p=0.005)greater for long-term and short-term recall,respectively.The agreement level was within the range21.2%to 25.9%for long-term recall,and24.2%to 28.5%for short-term recall.During a 5-day work week,day-to-day variation of sitting time was 9.4%§11.4%according to short-term recall and 10.4%§8.4%according to accelerometry-derived occupational sitting time.Conclusion:Overall,both long-term and short-term self-reported instruments provide acceptable measures of occupational sitting time in an office-based workplace,but their utility at the individual level is limited due to large variability.展开更多
According to the wire and nozzle movement track in groove, the movement parameters of wire were memorized and recalled for the following top welds by using a single chip computer. In this paper, it was also discussed...According to the wire and nozzle movement track in groove, the movement parameters of wire were memorized and recalled for the following top welds by using a single chip computer. In this paper, it was also discussed that the design problems of correcting deviation of wire movement track in narrow gap submerged arc welding process must be noticed in order to obtain the sound welding result.展开更多
This paper addressed a statistical analysis for the recall of parallel intraconnected bidirectional associative memory-Modified Intraconnected Bidirectional Associative Memory (MIBAM) and proved the conclusions: two M...This paper addressed a statistical analysis for the recall of parallel intraconnected bidirectional associative memory-Modified Intraconnected Bidirectional Associative Memory (MIBAM) and proved the conclusions: two MIBAM with the equal total number of neurons have the equal recalling probability for m pairs of stored pattern pairs if m is not too large. So they have the same capacity and same error correcting ability, i. e., their performances are statistically equivalent. The results of simulation support the conclusions well.展开更多
Purpose: To determine whether a global physical activity question (GPAq) administered in young adulthood can be used to accurately rank former physical activity levels (PA) relative to peers of the same age and sex du...Purpose: To determine whether a global physical activity question (GPAq) administered in young adulthood can be used to accurately rank former physical activity levels (PA) relative to peers of the same age and sex during adolescence. Methods: Data were obtained from the Physical Activity in Young Adults Study, a 10- year follow-up study of 12 - 16 year old adolescents. Five hundred twenty-eight young adults, mean age 24.5 (±1.0) years, completed a GPAq regarding current and past (adolescent) PA. GPAq answers were used to determine whether young adults could accurately rank their past (adolescent) PA levels relative to peers of the same age and sex. GPAq responses were compared with actual self-reported PA levels assessed by the Modifiable Activity Questionnaire for Adolescents (MAQ-A;collected during adolescence). For adolescent PA, an average of 4 years of activity from the MAQ-A 1990-1993, was used. Results: Regardless of gender, Jonckheere-Terpstra tests for trend (p < 0.0001) suggest significant linear trends across categories of PA level for the MAQ-A. Higher perceived PA tracked with greater past PA activity and lower perceived PA tracked with lower past PA activity. Conclusions: Young adults who classified themselves as more active as an adolescent were found to be relatively more active based upon self-reported activity from recall questionnaires collected during that time. These findings suggest that young adults can reasonably estimate relative PA levels during their adolescent years with GPAq. Global physical activity questions may be valid for the assessment and classification of previous PA levels.展开更多
Background: Early detection of dementia is currently of great interest and of crucial importance for the implementation of preventive measures and treatment of the disease. Impairment in verbal episodic memory, and in...Background: Early detection of dementia is currently of great interest and of crucial importance for the implementation of preventive measures and treatment of the disease. Impairment in verbal episodic memory, and in particular in a delayed recall phase, is considered one of the early markers of progression from mild cognitive impairment (MCI) to dementia. Therefore, having cognitive screening instruments with predictive value for progression is of utmost importance. Objective: The purpose of this work is to show the predictive value, sensitivity and specificity of the Memory Impairment Screen with delayed recall (MIS-DR) to predict conversion to dementia in patients with MCI. Methods: In retrospective study 502 patients over 60 years old, evaluated in the Older Adult Functional Evaluation Unit of our hospital for cognitive complaint, were diagnosed with MCI. They were followed up to assess conversion to dementia. Results: During follow up, 144 participants developed dementia (28.6%, 95% CI 24.76 - 32.85) and the average time of progression to dementia were 23 months (SD 13.2). The cut-off point was established below 6 for MIS-DR and it showed a sensitivity of 76% (95% CI 68.77 - 77.84) and a specificity of 56% (95% CI 50.44 - 61.58), with a positive predictive value of 41% (95% CI 34.78 - 47.6) and a negative predictive value of 85% (95% CI 80.53 - 91.11) for predicting progression to dementia. Of those patients who obtained a MIS-DR score below 6, 41% developed dementia, in contrast to 14.53% of those with a score above or equal to 6, OR 4.09 (95% CI 2.64 - 6.34), p 0.00001. There were no significant differences in terms of gender, education level or vascular risk factors among patients who converted and those who did not convert to dementia. Conclusion: We believe that MIS-DR is a useful and valid test to detect episodic memory impairment and to identify patients at risk of progression to dementia.展开更多
An experimental assessment of the effectiveness of university counselling was conducted through the “Stress Drawing Recall” Technique applied before and after a clinical colloquium with 70 university students of bot...An experimental assessment of the effectiveness of university counselling was conducted through the “Stress Drawing Recall” Technique applied before and after a clinical colloquium with 70 university students of both genders, aged 18 - 35 years, who had requested this service. Another 70 students waiting to undergo the colloquium were interviewed as a control group. Two parallel series of drawings depicting personal stress situations were collected and, after evaluation by three expert judges in “double-blind” conditions, led to establishing five forms of development of the graphic language from the first to second drawing, defined as follows: a) distension, with a reduction in stress indicators and increase in comfort indicators;b) explicit representation of conflict resolution;c) appearance of new elements, with persisting conflict;d) increase in stress indicators;e) invariant or equivalent repetition of the stress drawing. Results showed that students who underwent the clinical colloquium (experimental group) changed their stress drawings mainly in the direction of distension and conflict resolution, while the control group had more invariant or equivalent repetition of the stress situation (?= 62.77;p < 0.001). The events depicted in the stress drawings were divided into three categories: a) limited short-term stressful situations due to mainly external agents;b) externally induced stressful situations with intense emotional resonance;c) wide-ranging long-lasting stressful situations with great involvement of the self. The participants were divided into: a) very anxious subjects;b) averagely anxious subjects;c) not very anxious subjects, on the basis of their scores on two questionnaires: the MPI (1959) and the STAI (1970). There is a correspondence between the subjects’ level of conflict and extension of the depicted stress. This confirms the usefulness of the Stress Drawing Recall Technique in psychological counselling.展开更多
On aging, spatial memory declines to some degree in both, rodents and humans. It is unknown, however, whether aging brings about a decline of encoding and retrieval of spatial information in parallel. The present stud...On aging, spatial memory declines to some degree in both, rodents and humans. It is unknown, however, whether aging brings about a decline of encoding and retrieval of spatial information in parallel. The present study examined spatial encoding and retrieval in male CD-1 mice at 4, 9, and 12 months of age in a complex dry-land maze. The total time to reach the goal zone was age-dependent favoring mice at 4 months of age. We showed previously that moving time represents encoding of spatial information and resting time represents recall of previously learned spatial information. The average moving time decreased from 69.8 ± 5.3 s (mean ± SEM), 69.7 ± 8.0 s, and 78.9 ± 4.9 s to 17.0 ± 2.3 s (p < 0.001 ), 24.7 ± 2.7 s (p < 0.001), and 31.0 ± 3.5 s (p < 0.001) at 4, 9, and 12 months of age, respectively. The average resting time decreased from 34.9 ± 5.6 s, 22.2 ± 4.2 s, and 41.7 ± 5.3 s to 3.6 ± 1.2 s (p < 0.001), 5.3 ± 1.8 s (p = 0.009), and 22.7 ± 4.9 s (p = 0.007) at 4, 9, and 12 months of age, respectively. We conclude that age-related deficits of spatial memory in mice manifest with an encoding deficit prior to a retrieval deficit.展开更多
Radiation recall phenomenon is a tissue reaction that develops throughout a previously irradiated area,precipitated by the administration of certain drugs.Radiation recall is uncommon and easily neglected by physician...Radiation recall phenomenon is a tissue reaction that develops throughout a previously irradiated area,precipitated by the administration of certain drugs.Radiation recall is uncommon and easily neglected by physicians;hence,this phenomenon is underreported in literature.This manuscript reports two cases of radiation recall.First,a 44-year-old man with nasopharyngeal carcinoma was treated with radiotherapy in 2010 and subsequently developed multi-site bone metastases.A few days after the docetaxel-based chemotherapy,erythema and papules manifested dermatitis,as well as swallowing pain due to pharyngeal mucositis,developed on the head and neck that strictly corresponded to the previously irradiated areas.Second,a 19-year-old man with recurrent nasal NK/T cell lymphoma initially underwent radiotherapy followed by chemotherapy after five weeks.Erythema and edema appeared only at the irradiated skin.Both cases were considered chemotherapeutic agents that incurred radiation recall reactions.Clinicians should be knowledgeable of and pay attention to such rare phenomenon.展开更多
基金supported in part by the National Key Research and Development Program of China(2019YFB2204701)in part by the National Natural Science Foundation of China(61831006,62022023,and 62250610223)in part by the Big Data Computing Center at Southeast University for numerical calculation.
文摘This article proposes and demonstrates a retrodirective array(RDA)for two-way wireless communication with automatic beam tracking.The proposed RDA is enabled by specifically designed chips made using a domestic complementary metal-oxide semiconductor(CMOS)process.The highly integrated CMOS chip includes a receiving(Rx)chain,a transmitting(Tx)chain,and a unique tracking phaselocked loop(PLL)for the crucial conjugated phase recovery in the RDA.This article also proposes a method to reduce the beam pointing error(BPE)in a conventional RDA.To validate the above ideas simply yet without loss of generality,a 2.4 GHz RDA is demonstrated through two-way communication links between the Rx and Tx chains,and an on-chip quadrature coupler is designed to achieve a nonretrodirective signal suppression of 23 dBc.The experimental results demonstrate that the proposed RDA,which incorporates domestically manufactured low-cost 0.18 lm CMOS chips,is capable of automatically tracking beams covering±40with a reduced BPE.Each CMOS chip in the RDA has a compact size of 4.62 mm^(2) and a low power consumption of 0.15 W.To the best of the authors’knowledge,this is the first research to demonstrate an RDA with a fully customized CMOS chip for wireless communication with automatic beam tracking。
基金supported by the National Natural Science Foundation of China(Grant Nos.61505261,62101597,61605248,and 61675235)the National Key Research and Development Program of China(Grant No.2020YFA0309702)+2 种基金the China Postdoctoral Science Foundation(Grant No.2021M691536)the Natural Science Foundation of Henan Province(Grant Nos.202300410534 and 202300410532)the Anhui Initiative in Quantum Information Technologies.
文摘The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In this study,we apply the TWCC method to improve the performance of reference-frame-independent quantum key distribution(RFI-QKD),and analyze the influence of the TWCC method on the performance of decoy-state RFI-QKD in both asymptotic and non-asymptotic cases.Our numerical simulation results show that the TWCC method is able to extend the maximal transmission distance from 175 km to 198 km and improve the tolerable bit error rate from 10.48%to 16.75%.At the same time,the performance of RFI-QKD in terms of the secret key rate and maximum transmission distance are still greatly improved when statistical fluctuations are considered.We conclude that RFI-QKD with the TWCC method is of practical interest.
文摘The objective of this study was to experimentally evaluate children’s daily food memory and eating habits.The study found that the gender and school location had an impact on the nutritional condition of primary school students as well as the school food scheme.The investigations were based on three hypotheses and three research questions.In this study,the Eating Habits and Daily Dietary Recall Scale was the tool utilized to gather data(EPDDRS).Four experts—three from the department of vocational education and one lecturer in test and measurement evaluation—validated the instrument’s face.The dependability indices of EPDDRS were calculated using Cronbach’s Alpha.While delivering the instruments,the researcher used the direct administration and retrieval approach.58 instructors and a sample size of 1240 students were selected using a systematic random selection approach.The obtained data was examined using mean and standard deviation to address the research objectives,and the null hypotheses were tested using t-test statistics and Analysis of variance(ANOVA)at the 0.05 level of significance.The main conclusions of this study were that the school meal program had a favorable impact on the students’nutritional status.Also,a balanced ration of nutrient-dense meals that were suitably varied was supplied for the students via the school food program.Also,the findings revealed a substantial difference in the mean assessments of male and female students about their eating patterns.On the school meal program’s dietary recall list,students from high,middle,and low socioeconomic status differ significantly.Recommendations were given to the government,schools,and parents based on the study’s findings.The study’s shortcomings were discussed,and recommendations for more research were made.
基金supported in part by the National Natural Science Foundation of China (Nos.U22A2002, and 62071234)the Hainan Province Science and Technology Special Fund (ZDKJ2021022)+1 种基金the Scientific Research Fund Project of Hainan University under Grant KYQD(ZR)-21008the Collaborative Innovation Center of Information Technology, Hainan University (XTCX2022XXC07)
文摘In this paper,an intelligent reflecting surface(IRS)-and-unmanned aerial vehicle(UAV)-assisted two-way amplify-and-forward(AF)relay network in maritime Internet of Things(IoT)is proposed,where ship1(S1)and ship2(S2)can be viewed as data collecting centers.To enhance the message exchange rate between S1 and S2,a problem of maximizing minimum rate is cast,where the variables,namely AF relay beamforming matrix and IRS phase shifts of two time slots,need to be optimized.To achieve a maximum rate,a low-complexity alternately iterative(AI)scheme based on zero forcing and successive convex approximation(LC-ZF-SCA)algorithm is presented.To obtain a significant rate enhancement,a high-performance AI method based on one step,semidefinite programming and penalty SCA(ONSSDP-PSCA)is proposed.Simulation results show that by the proposed LC-ZF-SCA and ONS-SDP-PSCA methods,the rate of the IRS-and-UAV-assisted AF relay network surpass those of with random phase and only AF relay networks.Moreover,ONS-SDP-PSCA perform better than LC-ZF-SCA in aspect of rate.
基金supported in part by the National Natural Science Foundation of China under Grant 61971450in part by the Hunan Provincial Science and Technology Project Foundation under Grant 2018TP1018+1 种基金in part by the Natural Science Foundation of Hunan Province under Grant 2018JJ2533in part by Hunan Province College Students Research Learning and Innovative Experiment Project under Grant S202110542056。
文摘This paper investigates the security and reliability of information transmission within an underlay wiretap energy harvesting cognitive two-way relay network.In the network,energy-constrained secondary network(SN)nodes harvest energy from radio frequency signals of a multi-antenna power beacon.Two SN sources exchange their messages via a SN decode-and-forward relay in the presence of a multiantenna eavesdropper by using a four-phase time division broadcast protocol,and the hardware impairments of SN nodes and eavesdropper are modeled.To alleviate eavesdropping attacks,the artificial noise is applied by SN nodes.The physical layer security performance of SN is analyzed and evaluated by the exact closed-form expressions of outage probability(OP),intercept probability(IP),and OP+IP over quasistatic Rayleigh fading channel.Additionally,due to the complexity of OP+IP expression,a self-adaptive chaotic quantum particle swarm optimization-based resource allocation algorithm is proposed to jointly optimize energy harvesting ratio and power allocation factor,which can achieve security-reliability tradeoff for SN.Extensive simulations demonstrate the correctness of theoretical analysis and the effectiveness of the proposed optimization algorithm.
文摘Background: Cognitive impairment becomes more common with ageing and may benefit from intervention. In a Spanish speaking population, detection of cognitive impairment by a general practitioner in Primary Care can be a problem, as many of the standard tests target English speaking populations. The Memory Impairment Screen (MIS-A) is a validated test using English words to detect Alzheimer’s Disease (AD) and other dementias. We have modified this test to suit a Spanish speaking population and added a new component, delayed recall. We have called our new test the Memory Impairment Screen with Delayed Recall (MIS-D). Objectives: 1) To test a Spanish version of MIS-A and MIS-D. 2) To assess the discriminative validity of MIS-D as a screening tool for the amnestic variant of Mild Cognitive Impairment (aMCI) in a group of Spanish speaking people aged 65 years old and over. Methods: A case-control study of a cohort of 739 native Spanish speaking residents of Buenos Aires aged 65 years old and over, of whom 436 were healthy controls and 303 had a diagnosis of aMCI. Measurements: Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NVP) were estimated for MIS-D and MIS-A. Results: Normative values for MIS-A and MIS-D were obtained from the control population. Both age and education significantly affected these values (p < 0.0001). Control participants showed significant differences for both modalities, MIS-A and MIS-D. The cut-off for MIS-A should be 7.5 and for MIS-D, 5.5. Comparison between control population and aMCI population using ROC curve gave a result of 5.5 in MIS-D, with 97% specificity and 76% sensitivity. Conclusion: MIS-D was positively predictive of aMCI, with 97% specificity and 76% sensitivity in a sample of Spanish speaking patients aged 65 years old and over in Buenos Aires.
文摘A 57-year-old woman underwent abdominal surgery with a subarachnoid block supplemented by “light” general endotracheal anesthesia consisting of a propofol infusion and a sub-MAC concentration of sevoflurane. The previous case in the same operating room had involved a malignant hyperthermia-susceptible patient, and charcoal filters had been placed in the breathing circuit as a precautionary measure. Because it had not been used on the evening beforehand, the circuit with filters was left in situ with a strip of tape indicating that it was clean. The woman’s anesthesiologist assumed that these filters were heat and moisture exchanger filters in an unused circuit and therefore did not remove them. Subsequently, the patient had awareness with intraoperative recall. This case highlights the potential for inadvertent use of activated charcoal filters with potentially catastrophic results. Such unintended utilization of these products likely can be minimized by improved labeling techniques.
文摘<strong>Objective</strong><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of the International Physical Activity Questionnaire (IPAQ). </span><b><span style="font-family:Verdana;font-size:12px;">Methods</span></b></span><span style="font-family:Verdana;">:</span><span style="font-family:Verdana;"> IPAQ was evaluated for test-retest reliability within 6</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">-</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">8 days of its first administration. Criterion validity was tested comparing IPAQ data with those from an activity meter (Intelligent Device for Energy Expenditure and Activity, IDEEA). </span><b><span style="font-family:Verdana;font-size:12px;">Results</span></b><span style="font-family:Verdana;font-size:12px;">: The test-retest correlation (n = 71) for items of IPAQ ranged from r = 0.63 to r = 0.74 and w</span></span><span style="font-family:Verdana;">as </span><span style="font-family:Verdana;">r = 0.79 for the total weekly PA in MET*min per week. Average PA (in MET*min/week) measured with the IDEEA meter, decreased from normal (15</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">840), to 14</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">278 in overweight</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">(BMI</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">></span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">25-</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;"><</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">30) and further to 12</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">803 in obese subjects (>30. BMI). The weekly energy expenditure measured by IDEEA correlated significantly (r = 0</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">61,</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">r</span><sup><span style="font-family:Verdana;font-size:12px;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> = 0.38) with the IPAQ data, providing an objective criterion for validity of IPAQ. The mean values of weekly PA estimated from IPAQ (in MET*min/week) differed significantly in the high (15</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">690) vs. the low (11</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">398) activity groups but not between the moderate (12</span><span style="font-family:Verdana;">,</span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">056) compared to the low PA group. The IPAQ criteria used to categorize subjects as moderately active, erred by including too many low PA subjects. IDEEA measurements in sedentary subjects overestimated their energy expenditure. </span><b><span style="font-family:Verdana;font-size:12px;">Conclusions</span></b><span style="font-family:Verdana;font-size:12px;">: IPAQ can be reliably used to distinguish low and high PA groups and yields relatively low estimates (−</span></span><span style="font-family:Verdana;">18%) of weekly PA in these groups compared to those measured with the activity meter. Stricter criteria are needed to distinguish moderate from low PA groups. Overweight and obese subjects showed significantly lower levels of PA than normal BMI subjects.</span><span style="font-size:10pt;font-family:;" "=""> </span><span style="font-family:Verdana;">IDEEA overestimates low levels of PA.</span>
文摘BACKGROUND Radiation recall dermatitis has been defined as the "recalling" by skin of previous radiation exposure in response to the administration of certain response-inducing drugs. Although the phenomenon is relatively well known in the medical world,an exact cause has not been documented.CASE SUMMARY Here, we report the rare occurrence of radiation recall dermatitis after palliative radiotherapy for bone metastases in a metastatic melanoma patient treated with a combination of dabrafenib and trametinib.CONCLUSION We present a case of radiation recall dermatitis after completion of palliative radiotherapy while being treated with a combination of dabrafenib and trametinib. This is a very rare toxic event, and there is insufficient data to describe prevention strategies. Increased awareness and reporting of cases will help to better explain the association between targeted therapy and the radiation recall phenomenon.
基金supported by the China Scholarship Council(No.201206320092),China.
文摘Background:As sedentary behavior is a global health issue,there is a need for methods of self-reported sitting assessment.The accuracy and reliability of these methods should also be tested in various populations and different cultural contexts.This study examined the validity of longterm and short-term recall of occupational sitting time in Finnish and Chinese subgroups.Methods:Two cohort groups of office-based workers(58.6%female,age range 2267 years)participated:a Finnish group(FIN,n=34)and a Chinese group(CHI,n=36).Long-term(past 3-month sitting)and short-term(daily sitting assessed on 5 consecutive days)single-item measures were used to assess self-reported occupational sitting time.Values from each participant were compared to objectively measured occupational sitting time assessed via thigh-mounted accelerometers,with Spearman’s rho(r)used to assess validity and the Bland-Altman method used to evaluate agreement.Coefficients of variation depicted day-to-day variability of time spent on sitting at work.Results:In the total study sample,the results showed that both long-term and short-term recall correlated with accelerometer-derived sitting time(r=0.532,95%confidence intervals(CI):0.3360.684,p<0.001;r=0.533,95%CI:0.4490.607,p<0.001,respectively).Compared to objectively measured sitting time,self-reported occupational sitting time was 2.4%(95%CI:0.5%to 5.3%,p=0.091)and 2.2%(95%CI:0.7%3.6%,p=0.005)greater for long-term and short-term recall,respectively.The agreement level was within the range21.2%to 25.9%for long-term recall,and24.2%to 28.5%for short-term recall.During a 5-day work week,day-to-day variation of sitting time was 9.4%§11.4%according to short-term recall and 10.4%§8.4%according to accelerometry-derived occupational sitting time.Conclusion:Overall,both long-term and short-term self-reported instruments provide acceptable measures of occupational sitting time in an office-based workplace,but their utility at the individual level is limited due to large variability.
文摘According to the wire and nozzle movement track in groove, the movement parameters of wire were memorized and recalled for the following top welds by using a single chip computer. In this paper, it was also discussed that the design problems of correcting deviation of wire movement track in narrow gap submerged arc welding process must be noticed in order to obtain the sound welding result.
基金Supported by Climbing Program-National Key Project for Fundamental Research in China
文摘This paper addressed a statistical analysis for the recall of parallel intraconnected bidirectional associative memory-Modified Intraconnected Bidirectional Associative Memory (MIBAM) and proved the conclusions: two MIBAM with the equal total number of neurons have the equal recalling probability for m pairs of stored pattern pairs if m is not too large. So they have the same capacity and same error correcting ability, i. e., their performances are statistically equivalent. The results of simulation support the conclusions well.
文摘Purpose: To determine whether a global physical activity question (GPAq) administered in young adulthood can be used to accurately rank former physical activity levels (PA) relative to peers of the same age and sex during adolescence. Methods: Data were obtained from the Physical Activity in Young Adults Study, a 10- year follow-up study of 12 - 16 year old adolescents. Five hundred twenty-eight young adults, mean age 24.5 (±1.0) years, completed a GPAq regarding current and past (adolescent) PA. GPAq answers were used to determine whether young adults could accurately rank their past (adolescent) PA levels relative to peers of the same age and sex. GPAq responses were compared with actual self-reported PA levels assessed by the Modifiable Activity Questionnaire for Adolescents (MAQ-A;collected during adolescence). For adolescent PA, an average of 4 years of activity from the MAQ-A 1990-1993, was used. Results: Regardless of gender, Jonckheere-Terpstra tests for trend (p < 0.0001) suggest significant linear trends across categories of PA level for the MAQ-A. Higher perceived PA tracked with greater past PA activity and lower perceived PA tracked with lower past PA activity. Conclusions: Young adults who classified themselves as more active as an adolescent were found to be relatively more active based upon self-reported activity from recall questionnaires collected during that time. These findings suggest that young adults can reasonably estimate relative PA levels during their adolescent years with GPAq. Global physical activity questions may be valid for the assessment and classification of previous PA levels.
文摘Background: Early detection of dementia is currently of great interest and of crucial importance for the implementation of preventive measures and treatment of the disease. Impairment in verbal episodic memory, and in particular in a delayed recall phase, is considered one of the early markers of progression from mild cognitive impairment (MCI) to dementia. Therefore, having cognitive screening instruments with predictive value for progression is of utmost importance. Objective: The purpose of this work is to show the predictive value, sensitivity and specificity of the Memory Impairment Screen with delayed recall (MIS-DR) to predict conversion to dementia in patients with MCI. Methods: In retrospective study 502 patients over 60 years old, evaluated in the Older Adult Functional Evaluation Unit of our hospital for cognitive complaint, were diagnosed with MCI. They were followed up to assess conversion to dementia. Results: During follow up, 144 participants developed dementia (28.6%, 95% CI 24.76 - 32.85) and the average time of progression to dementia were 23 months (SD 13.2). The cut-off point was established below 6 for MIS-DR and it showed a sensitivity of 76% (95% CI 68.77 - 77.84) and a specificity of 56% (95% CI 50.44 - 61.58), with a positive predictive value of 41% (95% CI 34.78 - 47.6) and a negative predictive value of 85% (95% CI 80.53 - 91.11) for predicting progression to dementia. Of those patients who obtained a MIS-DR score below 6, 41% developed dementia, in contrast to 14.53% of those with a score above or equal to 6, OR 4.09 (95% CI 2.64 - 6.34), p 0.00001. There were no significant differences in terms of gender, education level or vascular risk factors among patients who converted and those who did not convert to dementia. Conclusion: We believe that MIS-DR is a useful and valid test to detect episodic memory impairment and to identify patients at risk of progression to dementia.
文摘An experimental assessment of the effectiveness of university counselling was conducted through the “Stress Drawing Recall” Technique applied before and after a clinical colloquium with 70 university students of both genders, aged 18 - 35 years, who had requested this service. Another 70 students waiting to undergo the colloquium were interviewed as a control group. Two parallel series of drawings depicting personal stress situations were collected and, after evaluation by three expert judges in “double-blind” conditions, led to establishing five forms of development of the graphic language from the first to second drawing, defined as follows: a) distension, with a reduction in stress indicators and increase in comfort indicators;b) explicit representation of conflict resolution;c) appearance of new elements, with persisting conflict;d) increase in stress indicators;e) invariant or equivalent repetition of the stress drawing. Results showed that students who underwent the clinical colloquium (experimental group) changed their stress drawings mainly in the direction of distension and conflict resolution, while the control group had more invariant or equivalent repetition of the stress situation (?= 62.77;p < 0.001). The events depicted in the stress drawings were divided into three categories: a) limited short-term stressful situations due to mainly external agents;b) externally induced stressful situations with intense emotional resonance;c) wide-ranging long-lasting stressful situations with great involvement of the self. The participants were divided into: a) very anxious subjects;b) averagely anxious subjects;c) not very anxious subjects, on the basis of their scores on two questionnaires: the MPI (1959) and the STAI (1970). There is a correspondence between the subjects’ level of conflict and extension of the depicted stress. This confirms the usefulness of the Stress Drawing Recall Technique in psychological counselling.
文摘On aging, spatial memory declines to some degree in both, rodents and humans. It is unknown, however, whether aging brings about a decline of encoding and retrieval of spatial information in parallel. The present study examined spatial encoding and retrieval in male CD-1 mice at 4, 9, and 12 months of age in a complex dry-land maze. The total time to reach the goal zone was age-dependent favoring mice at 4 months of age. We showed previously that moving time represents encoding of spatial information and resting time represents recall of previously learned spatial information. The average moving time decreased from 69.8 ± 5.3 s (mean ± SEM), 69.7 ± 8.0 s, and 78.9 ± 4.9 s to 17.0 ± 2.3 s (p < 0.001 ), 24.7 ± 2.7 s (p < 0.001), and 31.0 ± 3.5 s (p < 0.001) at 4, 9, and 12 months of age, respectively. The average resting time decreased from 34.9 ± 5.6 s, 22.2 ± 4.2 s, and 41.7 ± 5.3 s to 3.6 ± 1.2 s (p < 0.001), 5.3 ± 1.8 s (p = 0.009), and 22.7 ± 4.9 s (p = 0.007) at 4, 9, and 12 months of age, respectively. We conclude that age-related deficits of spatial memory in mice manifest with an encoding deficit prior to a retrieval deficit.
文摘Radiation recall phenomenon is a tissue reaction that develops throughout a previously irradiated area,precipitated by the administration of certain drugs.Radiation recall is uncommon and easily neglected by physicians;hence,this phenomenon is underreported in literature.This manuscript reports two cases of radiation recall.First,a 44-year-old man with nasopharyngeal carcinoma was treated with radiotherapy in 2010 and subsequently developed multi-site bone metastases.A few days after the docetaxel-based chemotherapy,erythema and papules manifested dermatitis,as well as swallowing pain due to pharyngeal mucositis,developed on the head and neck that strictly corresponded to the previously irradiated areas.Second,a 19-year-old man with recurrent nasal NK/T cell lymphoma initially underwent radiotherapy followed by chemotherapy after five weeks.Erythema and edema appeared only at the irradiated skin.Both cases were considered chemotherapeutic agents that incurred radiation recall reactions.Clinicians should be knowledgeable of and pay attention to such rare phenomenon.
