The mud shale of Qingshankou Formation in Songliao Basin is the main rock source and contains rich shale oil resources. The successful development of shale oil depends on evaluating and optimizing the “sweet spots”....The mud shale of Qingshankou Formation in Songliao Basin is the main rock source and contains rich shale oil resources. The successful development of shale oil depends on evaluating and optimizing the “sweet spots”. To accurately identify and optimize the favorable sweet spots of shale oil in Qingshankou Formation, Songliao Basin, the original logging data were preprocessed in this paper. Then the thin mud shale interlayer of Qingshankou Formation was identified effectively by using the processed logging data. Based on the artificial neural network method, the mineral content of mud shale in Qingshankou Formation was predicted. The lithofacies were identified according to the mineral and TOC content. Finally, a three-dimensional (3-D) model of total organic carbon (TOC), vitrinite reflectance (Ro), mineral content, and rock of Qingshankou Formation in Songliao Basin was established to evaluate and predict the favorable sweet spots of shale oil in the study area. The results show that there are a lot of calcareous and siliceous thin interlayers in Qingshankou Formation, and TOC content is generally between 2% and 3%. Ro is the highest in Gulong sag, followed by Sanzhao sag. The lithofacies mainly consists of felsic shale and mixed shale, mainly in the first member of Qingshankou Formation. Comprehensive analysis shows that shale oil development potential is enormous in the eastern part of Sanzhao Sag and the northern part of Gulong Sag.展开更多
Objective: MicroRNAs (miRNAs) are important regulators that play a key role in tumorigenesis and tumor progression. Transforming growth factor-β1 (TGF-β1) is involved in invasion and metastasis in many tumors. In th...Objective: MicroRNAs (miRNAs) are important regulators that play a key role in tumorigenesis and tumor progression. Transforming growth factor-β1 (TGF-β1) is involved in invasion and metastasis in many tumors. In this study, we investigated the microRNAs (miRNA) profiles altered by TGF-β1 in gastric cancer (GC) cells. Methods: We detected the expression profiles of miRNA by miRNA microarray and quantitative real-time polymerase chain reaction. Migration and invasion, wound-healing assay, prediction of miRNA targets, Western blot and qRT-PCR analysis were carried out to determine the role of one selected miRNA, namely miR-193b, in affecting the biological behaviors of GC BGC823 cells. Results: Among 847 human miRNAs in the microarray, three miRNAs (miR-27a, miR-29b-1 and miR-194) were up-regulated and three (miR-574-3p, miR-193b and miR-130b) were down-regulated in BGC823 cells treated with TGF-β1 compared with control. miR-193b suppressed the invasion and metastasis of GC cells in vivo and in vitro, and down-regulated urokinase-type plasminogen activator (uPA) protein in GC cells. Conclusions: TGF-β1 altered miRNA expression profile in BGC823 cells. Among the altered miRNAs, TGF-β1 induced the down-regulation of miR-193b, which inhibited cell invasion and metastasis in vivo and in vitro, and down-regulated uPA protein in GC cells.展开更多
R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2p...R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements.展开更多
Reaumuria soongorica and Salsola passerina have significant differences in ecophysiological characteristics, which change with the environmental variations. Although they live together for a long period of time, their...Reaumuria soongorica and Salsola passerina have significant differences in ecophysiological characteristics, which change with the environmental variations. Although they live together for a long period of time, their adaptive mechanisms to environmental stresses are very different. As two extreme xerophytes, Reaumuria soongorica and Salsola passerina differ significantly from other psammophytes in ecophysiological characteristics; they can survive in lower water potential, and can even grow in piedmont areas. Low water potential may be related to the existence of osmosis-regulating substance, such as praline, which can strengthen the capacity of water absorption. Compared to other psammophytes, Reaumuria soongorica and Salsola passerina have a higher degree of photo-inhibition under the same condition, and the photo-inhibition can lead to destruction of the photosynthetic pigment, nevertheless, this photo-inhibition can be repaired under suitable conditions in the morning and evening.展开更多
The wheat roots membrane separates the cell from the environment around it and encloses the cell contents. The pro-tein secondary structure and thermal stability of the plasma membrane of wheat root have been characte...The wheat roots membrane separates the cell from the environment around it and encloses the cell contents. The pro-tein secondary structure and thermal stability of the plasma membrane of wheat root have been characterized in D2O buffer from 20°C to 90°C by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Quantitative analysis of the amide I band (1700 - 1600 cm–1) showed that the plasma membrane proteins contains 41% α-helix, 16% β-sheet, 18% turn, and 25% disorder structures at 20°C. At elevated temperatures from 25°C up to 90°C, the α-helix and the β-sheet structure unfold into turns and the disorder structure, with a major conformational transition occurring at 50°C. There is a rapid decline in H+-ATPase activity of plasma membrane from 35°C to 55°C and it remain very low level H+-ATPase activity of PM from 55°C to 90°C. Therefore the protein conformational transition was one of reasons of loses H+-ATPase activity of plasma membrane.展开更多
Objective: To explore the effect of Daine-35 on serum hormone and antral follicle count of different subtypes of polycystic ovarian syndrome (PCOS). Methods: 138 cases of PCOS were recruited and typed according to Rot...Objective: To explore the effect of Daine-35 on serum hormone and antral follicle count of different subtypes of polycystic ovarian syndrome (PCOS). Methods: 138 cases of PCOS were recruited and typed according to Rotterdam diagnostic criteria;78 cases of tubal infertility without hyperandrogenism and menstrual disorders during the same period were collected as control. Serum reproductive hormones including follicle-stimulating hormone (FSH), luteotropic hormone (LH), prolactin (PRL), estradiol (E2), dehydroepiandrosterone (DHEAS), total testosterone (TT) and fast insulin (INS) were determined by chemiluminescent immunoassay. Ovarian antral follicle count was determined by ultrasonography. The effects on above indexes were evaluated for different subtypes of PCOS after 3 cycles of treatment with Daine-35. Results: The cases of Type A and Type B were respectively 43 (31.2%) and 73 (52.9%). They were the most common clinical phenotypes of PCOS in the central region ofChina. Total testosterone (TT) and DHEAS levels of Types A, C and D were higher than those of the control group (p < 0.05). The LH, LH/FSH, INS and HOMA-IR levels in all types of PCOS were higher than those of the control group (p < 0.05). Antral follicle counts of Types A, B and D were more than those of Type C and the control group (p < 0.05). After treatment with Daine-35 for 3 cycles, the serum TT levels of Types A, C and D decreased (p < 0.05). DHEAS values also decreased, but not significantly (p > 0.05). The serum LH and LH/FSH as well as the antral follicle count of all the PCOS types significantly decreased (p < 0.01). Conclusion: Type A and Type B are the most common clinical phenotypes of PCOS in the central region of China. Taking Daine-35 for 3 cycles can significantly reduce the serum androgen, serum LH, LH/FSH ratio, and antral follicle count of different PCOS types.展开更多
Investigation on fungal populations and mycotoxins of mouldy rapeseed was conducted in this paper. A total of 578 rapeseed samples were collected from 11 Chinese provinces in 2015, and 141 samples were contaminted by ...Investigation on fungal populations and mycotoxins of mouldy rapeseed was conducted in this paper. A total of 578 rapeseed samples were collected from 11 Chinese provinces in 2015, and 141 samples were contaminted by mycete. Mouldy rapeseed samples with exceeding specified standard were found in all areas. The highest percentages of samples were from Hunan, Jiangxi and Hubei provinces with above standard rate of 31.91%, 24.54% and 20.45% respectively. Mycete in 29 severely mouldy samples were isolatedand determined by using dilution method. Eighty-three dominant isolates were found,among which fungal strain number ranged from 1 to 8. Aspergillus flavus, Penicillium steckii and Penicillium citrinum were dominant myco-populations identified by morphological and molecular biological methods. Rapeseed from the Southern provinces including Jiangxi,Hunan and Guangxi were contaminated by more isolates. Mycotoxins content were evaluated by LC–MS/MS. AFB1, BEA and FB1 were the top 3 prevalent mycotoxins. BEA and FB1 contaminations in rapeseed were relatively low. This investigation provid support for protecting public health and ensuring consumption security of rapeseed.展开更多
Background Immunotherapy shows promise as a treatment option for various cancers.However,there is growing concern over potential complications from hepatitis B virus(HBV)reactivation after checkpoint blockade immunoth...Background Immunotherapy shows promise as a treatment option for various cancers.However,there is growing concern over potential complications from hepatitis B virus(HBV)reactivation after checkpoint blockade immunotherapy.Although most of the previous clinical trials on immune checkpoint inhibitors(ICIs)excluded patients with HBV,a few case reports and retrospective studies of HBV reactivation have been published.The aim of this study is to assess the risk of hepatitis B virus reactivation(HBVr)in patients receiving ICIs for advanced cancer.Methods English and Chinese language literature published prior to April 30,2023,was searched in PubMed,EMBASE,Web of Science,Cochrane,SinoMed,CNKI and Wanfang Data for studies reporting HBVr rates in cancer patients treated with ICIs.A pooled risk estimate was calculated for HBVr rates with 95%confdence intervals(CI).Results Data from 34 studies including 7126 patients were retrieved and analyzed.The pooled HBVr rate in cancer patients treated with ICIs was 1.3%(I^(2)=90.44%,95%CI:0.2-2.9%,P<0.001).Subgroup analysis revealed that patients diagnosed with hepatocellular carcinoma(HCC),HBV carriers,and patients from Asian regions or in developing countries have a higher rate of HBVr.Conclusions Our meta-analysis demonstrated a low risk of HBVr in patients treated with ICIs for advanced cancer.ICI treatment may be safely used in patients with existing HBV infection or chronic hepatitis B,accompanied by regular monitoring and appropriate antiviral prophylaxis if necessary.展开更多
As persulfate(S_(2)O_(8)^(2-))is being increasingly used as an alternative oxidizing agent,developing lowcost and eco-friendly catalysts for efficient S_(2)O_(8)^(2-)activation is potentially useful for the treatment ...As persulfate(S_(2)O_(8)^(2-))is being increasingly used as an alternative oxidizing agent,developing lowcost and eco-friendly catalysts for efficient S_(2)O_(8)^(2-)activation is potentially useful for the treatment of wastewater containing refractory organic pollutant.In this study,the degradative features and mechanisms of carbamazepine(CBZ)were systematically investigated in a novel FeS-S_(2)O_(8)^(2-)process under near-neutral conditions.The results exhibited that CBZ can be effectively eliminated by the FeS-S_(2)O_(8)^(2-)process and the optimal conditions were:250 mg/L FeS,0.5 mmol/L S_(2)O_(8)^(2-),and pH=6.0.The existence of Cl^(−)(1 and 50 mmol/L)has little influence on the CBZ elimination,while both HCO_(3)^(−) and HPO_(4)^(2−)(1 and 50 mmol/L)significantly suppressed the CBZ removal in the FeS-S_(2)O_(8)^(2-)process.CBZ could be degraded via a radical mechanism in the FeS-S_(2)O_(8)^(2-)process,the working radical species(i.e.,SO_(4)•−and•OH)were efficiently formed via the promoted decomposition of S_(2)O_(8)^(2-)by the surface Fe2+on the FeS and the dissolved ferrous ions in solution.Based on the identified oxidized products and Fukui index calculations,a possible degradation pathway of CBZ was speculated.More importantly,a two-stage oxidation mechanism of CBZ elimination was speculated in the FeS-S_(2)O_(8)^(2-)process,the activation of S_(2)O_(8)^(2-)by the surface-active Fe(II)of FeS dominated in the initial 5 min,while homogeneous oxidation reactions played more essential parts than others in the following reaction stage(5–60 min).Overall,this study demonstrated that the FeS-S_(2)O_(8)^(2-)process is capable of removing CBZ from water efficiently.展开更多
To the Editor:Parkinson’s disease(PD)is one of the most common neurodegenerative movement disorders.[1]Its cardinal symptoms include bradykinesia,tremor,and rigidity.[2]The severity of PD-related motor symptoms is us...To the Editor:Parkinson’s disease(PD)is one of the most common neurodegenerative movement disorders.[1]Its cardinal symptoms include bradykinesia,tremor,and rigidity.[2]The severity of PD-related motor symptoms is usually semiquantitatively evaluated by the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale(MDS-UPDRS)[3]part three(MDS-UPDRS III).A series of machine perception and machine learning technologies have been applied to assist the manual rating of motor symptoms.[4,5]Machine vision,which does not require physical contact between the examiner and the patient.展开更多
The high moisture content (80%) in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification (S/S) alternative for the sludge was developed, usi...The high moisture content (80%) in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification (S/S) alternative for the sludge was developed, using calcined aluminum salts (AS) as solidifier, and CaCl 2 , Na 2 SO 4 and CaSO 4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS 0 obtained with 5% AS and 10% CaSO 4 of AS by weight presented a moisture contents below 50%–60% and a compressive strength of (51.32 ± 2.9) kPa after 5–7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO 4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry- differential scanning calorimetry investigations revealed that a large amount of hydrates (viz., gismondine and CaCO 3 ) were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure (TCLP) and horizontal vibration (HJ 557-2009) leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill.展开更多
In this paper, we investigate if dividend policy is influenced by ownership type.Within the dividend literature, dividends have a signaling role regarding agency costs, such that dividends may diminish insider conflic...In this paper, we investigate if dividend policy is influenced by ownership type.Within the dividend literature, dividends have a signaling role regarding agency costs, such that dividends may diminish insider conflicts(reduce free cash flow) or may be used to extract cash from firms(tunneling effect)- which could be predominant in emerging markets. We expect firms with foreign ownership and those that are listed in overseas markets to have different dividend policies and practices than those that are not, and firms with more state ownership and less individual ownership to be more likely to pay cash dividends and less likely to pay stock dividends. Using firms from an emerging economy(China), we examine whether these effects exist in corporate dividend policy and practice. We find that both foreign ownership and cross-listing have significant negative effects on cash dividends, consistent with the signaling effect and the notion of reduced tunneling activities for firms with the ability to raise capital from outside of China. Consistent with the tunneling effect, we find that firms with higher state ownership tend to pay higher cash dividends and lower stock dividends, while the opposite is true for public(individual) ownership.Further analysis shows that foreign ownership mediates the effect of state ownership on dividend policy. Our results have significant implications for researchers, investors, policy makers and regulators in emerging markets.展开更多
Background:There is an urgent need for developing objective,effective and convenient measurements to help clinicians accurately identify bradykinesia.The purpose of this study is to evaluate the accuracy of an objecti...Background:There is an urgent need for developing objective,effective and convenient measurements to help clinicians accurately identify bradykinesia.The purpose of this study is to evaluate the accuracy of an objective approach assessing bradykinesia in finger tapping(FT)that uses evolutionary algorithms(EAs)and explore whether it can be used to identify early stage Parkinson’s disease(PD).Methods:One hundred and seven PD,41 essential tremor(ET)patients and 49 normal controls(NC)were recruited.Participants performed a standard FT task with two electromagnetic tracking sensors attached to the thumb and index finger.Readings from the sensors were transmitted to a tablet computer and subsequently analyzed by using EAs.The output from the device(referred to as"PD-Monitor")scaled from−1 to+1(where higher scores indicate greater severity of bradykinesia).Meanwhile,the bradykinesia was rated clinically using the Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale(MDS-UPDRS)FT item.Results:With an increasing MDS-UPDRS FT score,the PD-Monitor score from the same hand side increased correspondingly.PD-Monitor score correlated well with MDS-UPDRS FT score(right side:r=0.819,P=0.000;left side:r=0.783,P=0.000).Moreover,PD-Monitor scores in 97 PD patients with MDS-UPDRS FT bradykinesia and each PD subgroup(FT bradykinesia scored from 1 to 3)were all higher than that in NC.Receiver operating characteristic(ROC)curves revealed that PD-Monitor FT scores could detect different severity of bradykinesia with high accuracy(≥89.7%)in the right dominant hand.Furthermore,PD-Monitor scores could discriminate early stage PD from NC,with area under the ROC curve greater than or equal to 0.899.Additionally,ET without bradykinesia could be differentiated from PD by PD-Monitor scores.A positive correlation of PD-Monitor scores with modified Hoehn and Yahr stage was found in the left hand sides.Conclusions:Our study demonstrated that a simple to use device employing classifiers derived from EAs could not only be used to accurately measure different severity of bradykinesia in PD,but also had the potential to differentiate early stage PD from normality.展开更多
This study examines the effect of corporate ownership on information asymmetry as measured by bid-ask spread in the emerging markets of China. Government ownership has significant and positive impacts on bid-ask sprea...This study examines the effect of corporate ownership on information asymmetry as measured by bid-ask spread in the emerging markets of China. Government ownership has significant and positive impacts on bid-ask spread during the period 1995-2000, but disappears afterward during 2001-2003. The finding that state ownership raised bid-ask spread in the early period is consistent with recent studies on emerging markets including China, which indicate that firms with higher state ownership tend to have a greater deviation between cash flow rights and control rights(eg, Wei et al., 2005). This implies that lower state ownership is associated with lower information asymmetry in the market, an economic consequence of significant economic reform and privatization regarding the market microstructure. However, with more active control transfers andemergence of private controlling shareholders, regulatory changes in ownership structure and corporate governance mechanisms, and thus an improved legal and institutional environment, the link between the government ownership and information asymmetry turns to be insignificant in the later period. These results have important implications for transparency and information disclosure policies as well as privatization in emerging markets.展开更多
White adipose tissue(WAT)is a highly plastic organ that plays a central role in regulating whole-body energy metabolism.Adipose stem and progenitor cells(ASPCs)are essential components of the stromal vascular fraction...White adipose tissue(WAT)is a highly plastic organ that plays a central role in regulating whole-body energy metabolism.Adipose stem and progenitor cells(ASPCs)are essential components of the stromal vascular fraction(SVF)of adipose tissue.They give rise to mature adipocytes and play a critical role in maintaining adipose tissue function.However,the molecular heterogeneity and functional diversity of ASPCs are still poorly understood.Recently,single-cell RNA sequencing(scRNA-seq)analysis has identified distinct subtypes of ASPCs in murine and human adipose tissues,providing new insights into the cellular complexity of ASPCs among multiple fat depots.This review summarizes the current knowledge on ASPC populations,including their markers,functions,and regulatory mechanisms.Targeting one or several of these cell populations may ameliorate metabolic disorders by promoting adaptive hyperplastic adipose growth.展开更多
In this paper, we first propose the maximum arc problem, normal rational curve conjecture, and extensions of normal rational curves over finite local rings, analogously to the finite geometry over finite fields. We th...In this paper, we first propose the maximum arc problem, normal rational curve conjecture, and extensions of normal rational curves over finite local rings, analogously to the finite geometry over finite fields. We then study the deep hole problem of generalized Reed-Solomon (RS) codes over finite local rings. Several different classes of deep holes are constructed. The relationship between finite geometry and deep holes of RS codes over finite local rings are also studied.展开更多
文摘The mud shale of Qingshankou Formation in Songliao Basin is the main rock source and contains rich shale oil resources. The successful development of shale oil depends on evaluating and optimizing the “sweet spots”. To accurately identify and optimize the favorable sweet spots of shale oil in Qingshankou Formation, Songliao Basin, the original logging data were preprocessed in this paper. Then the thin mud shale interlayer of Qingshankou Formation was identified effectively by using the processed logging data. Based on the artificial neural network method, the mineral content of mud shale in Qingshankou Formation was predicted. The lithofacies were identified according to the mineral and TOC content. Finally, a three-dimensional (3-D) model of total organic carbon (TOC), vitrinite reflectance (Ro), mineral content, and rock of Qingshankou Formation in Songliao Basin was established to evaluate and predict the favorable sweet spots of shale oil in the study area. The results show that there are a lot of calcareous and siliceous thin interlayers in Qingshankou Formation, and TOC content is generally between 2% and 3%. Ro is the highest in Gulong sag, followed by Sanzhao sag. The lithofacies mainly consists of felsic shale and mixed shale, mainly in the first member of Qingshankou Formation. Comprehensive analysis shows that shale oil development potential is enormous in the eastern part of Sanzhao Sag and the northern part of Gulong Sag.
基金supported by Natural Science Foundation of China(No.81001080)Natural Science Foundation of China(No.30901452)
文摘Objective: MicroRNAs (miRNAs) are important regulators that play a key role in tumorigenesis and tumor progression. Transforming growth factor-β1 (TGF-β1) is involved in invasion and metastasis in many tumors. In this study, we investigated the microRNAs (miRNA) profiles altered by TGF-β1 in gastric cancer (GC) cells. Methods: We detected the expression profiles of miRNA by miRNA microarray and quantitative real-time polymerase chain reaction. Migration and invasion, wound-healing assay, prediction of miRNA targets, Western blot and qRT-PCR analysis were carried out to determine the role of one selected miRNA, namely miR-193b, in affecting the biological behaviors of GC BGC823 cells. Results: Among 847 human miRNAs in the microarray, three miRNAs (miR-27a, miR-29b-1 and miR-194) were up-regulated and three (miR-574-3p, miR-193b and miR-130b) were down-regulated in BGC823 cells treated with TGF-β1 compared with control. miR-193b suppressed the invasion and metastasis of GC cells in vivo and in vitro, and down-regulated urokinase-type plasminogen activator (uPA) protein in GC cells. Conclusions: TGF-β1 altered miRNA expression profile in BGC823 cells. Among the altered miRNAs, TGF-β1 induced the down-regulation of miR-193b, which inhibited cell invasion and metastasis in vivo and in vitro, and down-regulated uPA protein in GC cells.
文摘R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements.
基金supported by the National Natural Science Foundation of China (No. 30870383 and No. 30740051)the National Key Technology R&D Program of China(No. 2007BAD54B05 and No. 2008BAC39B04)
文摘Reaumuria soongorica and Salsola passerina have significant differences in ecophysiological characteristics, which change with the environmental variations. Although they live together for a long period of time, their adaptive mechanisms to environmental stresses are very different. As two extreme xerophytes, Reaumuria soongorica and Salsola passerina differ significantly from other psammophytes in ecophysiological characteristics; they can survive in lower water potential, and can even grow in piedmont areas. Low water potential may be related to the existence of osmosis-regulating substance, such as praline, which can strengthen the capacity of water absorption. Compared to other psammophytes, Reaumuria soongorica and Salsola passerina have a higher degree of photo-inhibition under the same condition, and the photo-inhibition can lead to destruction of the photosynthetic pigment, nevertheless, this photo-inhibition can be repaired under suitable conditions in the morning and evening.
文摘The wheat roots membrane separates the cell from the environment around it and encloses the cell contents. The pro-tein secondary structure and thermal stability of the plasma membrane of wheat root have been characterized in D2O buffer from 20°C to 90°C by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Quantitative analysis of the amide I band (1700 - 1600 cm–1) showed that the plasma membrane proteins contains 41% α-helix, 16% β-sheet, 18% turn, and 25% disorder structures at 20°C. At elevated temperatures from 25°C up to 90°C, the α-helix and the β-sheet structure unfold into turns and the disorder structure, with a major conformational transition occurring at 50°C. There is a rapid decline in H+-ATPase activity of plasma membrane from 35°C to 55°C and it remain very low level H+-ATPase activity of PM from 55°C to 90°C. Therefore the protein conformational transition was one of reasons of loses H+-ATPase activity of plasma membrane.
文摘Objective: To explore the effect of Daine-35 on serum hormone and antral follicle count of different subtypes of polycystic ovarian syndrome (PCOS). Methods: 138 cases of PCOS were recruited and typed according to Rotterdam diagnostic criteria;78 cases of tubal infertility without hyperandrogenism and menstrual disorders during the same period were collected as control. Serum reproductive hormones including follicle-stimulating hormone (FSH), luteotropic hormone (LH), prolactin (PRL), estradiol (E2), dehydroepiandrosterone (DHEAS), total testosterone (TT) and fast insulin (INS) were determined by chemiluminescent immunoassay. Ovarian antral follicle count was determined by ultrasonography. The effects on above indexes were evaluated for different subtypes of PCOS after 3 cycles of treatment with Daine-35. Results: The cases of Type A and Type B were respectively 43 (31.2%) and 73 (52.9%). They were the most common clinical phenotypes of PCOS in the central region ofChina. Total testosterone (TT) and DHEAS levels of Types A, C and D were higher than those of the control group (p < 0.05). The LH, LH/FSH, INS and HOMA-IR levels in all types of PCOS were higher than those of the control group (p < 0.05). Antral follicle counts of Types A, B and D were more than those of Type C and the control group (p < 0.05). After treatment with Daine-35 for 3 cycles, the serum TT levels of Types A, C and D decreased (p < 0.05). DHEAS values also decreased, but not significantly (p > 0.05). The serum LH and LH/FSH as well as the antral follicle count of all the PCOS types significantly decreased (p < 0.01). Conclusion: Type A and Type B are the most common clinical phenotypes of PCOS in the central region of China. Taking Daine-35 for 3 cycles can significantly reduce the serum androgen, serum LH, LH/FSH ratio, and antral follicle count of different PCOS types.
文摘Investigation on fungal populations and mycotoxins of mouldy rapeseed was conducted in this paper. A total of 578 rapeseed samples were collected from 11 Chinese provinces in 2015, and 141 samples were contaminted by mycete. Mouldy rapeseed samples with exceeding specified standard were found in all areas. The highest percentages of samples were from Hunan, Jiangxi and Hubei provinces with above standard rate of 31.91%, 24.54% and 20.45% respectively. Mycete in 29 severely mouldy samples were isolatedand determined by using dilution method. Eighty-three dominant isolates were found,among which fungal strain number ranged from 1 to 8. Aspergillus flavus, Penicillium steckii and Penicillium citrinum were dominant myco-populations identified by morphological and molecular biological methods. Rapeseed from the Southern provinces including Jiangxi,Hunan and Guangxi were contaminated by more isolates. Mycotoxins content were evaluated by LC–MS/MS. AFB1, BEA and FB1 were the top 3 prevalent mycotoxins. BEA and FB1 contaminations in rapeseed were relatively low. This investigation provid support for protecting public health and ensuring consumption security of rapeseed.
文摘Background Immunotherapy shows promise as a treatment option for various cancers.However,there is growing concern over potential complications from hepatitis B virus(HBV)reactivation after checkpoint blockade immunotherapy.Although most of the previous clinical trials on immune checkpoint inhibitors(ICIs)excluded patients with HBV,a few case reports and retrospective studies of HBV reactivation have been published.The aim of this study is to assess the risk of hepatitis B virus reactivation(HBVr)in patients receiving ICIs for advanced cancer.Methods English and Chinese language literature published prior to April 30,2023,was searched in PubMed,EMBASE,Web of Science,Cochrane,SinoMed,CNKI and Wanfang Data for studies reporting HBVr rates in cancer patients treated with ICIs.A pooled risk estimate was calculated for HBVr rates with 95%confdence intervals(CI).Results Data from 34 studies including 7126 patients were retrieved and analyzed.The pooled HBVr rate in cancer patients treated with ICIs was 1.3%(I^(2)=90.44%,95%CI:0.2-2.9%,P<0.001).Subgroup analysis revealed that patients diagnosed with hepatocellular carcinoma(HCC),HBV carriers,and patients from Asian regions or in developing countries have a higher rate of HBVr.Conclusions Our meta-analysis demonstrated a low risk of HBVr in patients treated with ICIs for advanced cancer.ICI treatment may be safely used in patients with existing HBV infection or chronic hepatitis B,accompanied by regular monitoring and appropriate antiviral prophylaxis if necessary.
基金the National Natural Science Foundation of China(No.52100060)the Natural Science Foundation of Hubei Province,China(No.2020CFB383)for the financial support。
文摘As persulfate(S_(2)O_(8)^(2-))is being increasingly used as an alternative oxidizing agent,developing lowcost and eco-friendly catalysts for efficient S_(2)O_(8)^(2-)activation is potentially useful for the treatment of wastewater containing refractory organic pollutant.In this study,the degradative features and mechanisms of carbamazepine(CBZ)were systematically investigated in a novel FeS-S_(2)O_(8)^(2-)process under near-neutral conditions.The results exhibited that CBZ can be effectively eliminated by the FeS-S_(2)O_(8)^(2-)process and the optimal conditions were:250 mg/L FeS,0.5 mmol/L S_(2)O_(8)^(2-),and pH=6.0.The existence of Cl^(−)(1 and 50 mmol/L)has little influence on the CBZ elimination,while both HCO_(3)^(−) and HPO_(4)^(2−)(1 and 50 mmol/L)significantly suppressed the CBZ removal in the FeS-S_(2)O_(8)^(2-)process.CBZ could be degraded via a radical mechanism in the FeS-S_(2)O_(8)^(2-)process,the working radical species(i.e.,SO_(4)•−and•OH)were efficiently formed via the promoted decomposition of S_(2)O_(8)^(2-)by the surface Fe2+on the FeS and the dissolved ferrous ions in solution.Based on the identified oxidized products and Fukui index calculations,a possible degradation pathway of CBZ was speculated.More importantly,a two-stage oxidation mechanism of CBZ elimination was speculated in the FeS-S_(2)O_(8)^(2-)process,the activation of S_(2)O_(8)^(2-)by the surface-active Fe(II)of FeS dominated in the initial 5 min,while homogeneous oxidation reactions played more essential parts than others in the following reaction stage(5–60 min).Overall,this study demonstrated that the FeS-S_(2)O_(8)^(2-)process is capable of removing CBZ from water efficiently.
基金National Natural Science Foundation of China(Nos.82230040,82071415,and 81971183)Shanghai Jiao Tong University Trans-med Awards Research(No.20220103)
文摘To the Editor:Parkinson’s disease(PD)is one of the most common neurodegenerative movement disorders.[1]Its cardinal symptoms include bradykinesia,tremor,and rigidity.[2]The severity of PD-related motor symptoms is usually semiquantitatively evaluated by the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale(MDS-UPDRS)[3]part three(MDS-UPDRS III).A series of machine perception and machine learning technologies have been applied to assist the manual rating of motor symptoms.[4,5]Machine vision,which does not require physical contact between the examiner and the patient.
基金supported by the Science and Technol- ogy Commission of Shanghai Municipality (No. 08DZ 1202802, 09DZ 1204105)
文摘The high moisture content (80%) in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification (S/S) alternative for the sludge was developed, using calcined aluminum salts (AS) as solidifier, and CaCl 2 , Na 2 SO 4 and CaSO 4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS 0 obtained with 5% AS and 10% CaSO 4 of AS by weight presented a moisture contents below 50%–60% and a compressive strength of (51.32 ± 2.9) kPa after 5–7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO 4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry- differential scanning calorimetry investigations revealed that a large amount of hydrates (viz., gismondine and CaCO 3 ) were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure (TCLP) and horizontal vibration (HJ 557-2009) leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill.
文摘In this paper, we investigate if dividend policy is influenced by ownership type.Within the dividend literature, dividends have a signaling role regarding agency costs, such that dividends may diminish insider conflicts(reduce free cash flow) or may be used to extract cash from firms(tunneling effect)- which could be predominant in emerging markets. We expect firms with foreign ownership and those that are listed in overseas markets to have different dividend policies and practices than those that are not, and firms with more state ownership and less individual ownership to be more likely to pay cash dividends and less likely to pay stock dividends. Using firms from an emerging economy(China), we examine whether these effects exist in corporate dividend policy and practice. We find that both foreign ownership and cross-listing have significant negative effects on cash dividends, consistent with the signaling effect and the notion of reduced tunneling activities for firms with the ability to raise capital from outside of China. Consistent with the tunneling effect, we find that firms with higher state ownership tend to pay higher cash dividends and lower stock dividends, while the opposite is true for public(individual) ownership.Further analysis shows that foreign ownership mediates the effect of state ownership on dividend policy. Our results have significant implications for researchers, investors, policy makers and regulators in emerging markets.
基金This work was supported by the National Natural Science Foundation of China(grant numbers.81430022,81771374).
文摘Background:There is an urgent need for developing objective,effective and convenient measurements to help clinicians accurately identify bradykinesia.The purpose of this study is to evaluate the accuracy of an objective approach assessing bradykinesia in finger tapping(FT)that uses evolutionary algorithms(EAs)and explore whether it can be used to identify early stage Parkinson’s disease(PD).Methods:One hundred and seven PD,41 essential tremor(ET)patients and 49 normal controls(NC)were recruited.Participants performed a standard FT task with two electromagnetic tracking sensors attached to the thumb and index finger.Readings from the sensors were transmitted to a tablet computer and subsequently analyzed by using EAs.The output from the device(referred to as"PD-Monitor")scaled from−1 to+1(where higher scores indicate greater severity of bradykinesia).Meanwhile,the bradykinesia was rated clinically using the Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale(MDS-UPDRS)FT item.Results:With an increasing MDS-UPDRS FT score,the PD-Monitor score from the same hand side increased correspondingly.PD-Monitor score correlated well with MDS-UPDRS FT score(right side:r=0.819,P=0.000;left side:r=0.783,P=0.000).Moreover,PD-Monitor scores in 97 PD patients with MDS-UPDRS FT bradykinesia and each PD subgroup(FT bradykinesia scored from 1 to 3)were all higher than that in NC.Receiver operating characteristic(ROC)curves revealed that PD-Monitor FT scores could detect different severity of bradykinesia with high accuracy(≥89.7%)in the right dominant hand.Furthermore,PD-Monitor scores could discriminate early stage PD from NC,with area under the ROC curve greater than or equal to 0.899.Additionally,ET without bradykinesia could be differentiated from PD by PD-Monitor scores.A positive correlation of PD-Monitor scores with modified Hoehn and Yahr stage was found in the left hand sides.Conclusions:Our study demonstrated that a simple to use device employing classifiers derived from EAs could not only be used to accurately measure different severity of bradykinesia in PD,but also had the potential to differentiate early stage PD from normality.
文摘This study examines the effect of corporate ownership on information asymmetry as measured by bid-ask spread in the emerging markets of China. Government ownership has significant and positive impacts on bid-ask spread during the period 1995-2000, but disappears afterward during 2001-2003. The finding that state ownership raised bid-ask spread in the early period is consistent with recent studies on emerging markets including China, which indicate that firms with higher state ownership tend to have a greater deviation between cash flow rights and control rights(eg, Wei et al., 2005). This implies that lower state ownership is associated with lower information asymmetry in the market, an economic consequence of significant economic reform and privatization regarding the market microstructure. However, with more active control transfers andemergence of private controlling shareholders, regulatory changes in ownership structure and corporate governance mechanisms, and thus an improved legal and institutional environment, the link between the government ownership and information asymmetry turns to be insignificant in the later period. These results have important implications for transparency and information disclosure policies as well as privatization in emerging markets.
基金supported by the National Key R&D Program of China (2020YFA0803604)the National Natural Science Foundation of China (81770868, 91742103, 82130024 and 82170866)+1 种基金the Science and Technology Innovation Program of Hunan Province (2020RC4009)the Project of Innovation-Driven Plan of Central South University (2020CX015)
文摘White adipose tissue(WAT)is a highly plastic organ that plays a central role in regulating whole-body energy metabolism.Adipose stem and progenitor cells(ASPCs)are essential components of the stromal vascular fraction(SVF)of adipose tissue.They give rise to mature adipocytes and play a critical role in maintaining adipose tissue function.However,the molecular heterogeneity and functional diversity of ASPCs are still poorly understood.Recently,single-cell RNA sequencing(scRNA-seq)analysis has identified distinct subtypes of ASPCs in murine and human adipose tissues,providing new insights into the cellular complexity of ASPCs among multiple fat depots.This review summarizes the current knowledge on ASPC populations,including their markers,functions,and regulatory mechanisms.Targeting one or several of these cell populations may ameliorate metabolic disorders by promoting adaptive hyperplastic adipose growth.
基金The research of Jun Zhang was supported by the National Natural Science Foundation of China(Grant No.11971321)by National Key Research and Development Program of China(Grant No.2018YFA0704703)The research of Haiyan Zhou was supported by the National Natural Science Foundation of China(Grant No.12071221).
文摘In this paper, we first propose the maximum arc problem, normal rational curve conjecture, and extensions of normal rational curves over finite local rings, analogously to the finite geometry over finite fields. We then study the deep hole problem of generalized Reed-Solomon (RS) codes over finite local rings. Several different classes of deep holes are constructed. The relationship between finite geometry and deep holes of RS codes over finite local rings are also studied.
