The flow duration curve (FDC) is the cumulative distribution function, which represents the relationship between the frequency and magnitude of streamflow, and the precipitation duration curves (PDC) ...follows the same principle. Nowadays, the correlation between the shape of PDC and FDCs, their respective physical control factors including human activities, and their fitting conditions in unmeasured catchments across China have not been fully understood. In this paper, daily precipitation and streamflow data with 30 years records from 224 hydrological stations in the middle and lower Yangtze River basin were chosen to fit PDC and FDCs through gamma distribution. Framework was proposed for modelling FDCs to analyse the relationship, similarity, regional patterns and response mechanism of fitting parameters between PDC and FDCs, dividing the streamflow time series into fast and base flow and stations into three categories in consideration of human activities to attribute the shapes of PDC and FDCs to catchment meteorological and geographical characteristics and physical processes under natural conditions. Results indicate that the parameters of PDC and certain FDCs (TFDC, FFDC, SFDC) share similar spatial patterns but vary for the different duration and interactions of the processes. The climate and catchment characteristics such as extreme properties of precipitation, base flow index (BFI), Pmax*αp and concentration ratio index (CIM) will influence the shape of PDC and FDCs. The relationship between BFI and SFDC/TFDC can be better reflected in “Regulated watersheds”, while CIM/Pmax*αp and PDC/FFDC in “watersheds in the mainstream” are more related. This paper provides a deeper understanding and more accurate way of the application of these parameters in describing and predicting hydrological processes and estimation of PDC and FDCs in unmeasured catchments, and can be applied to more future research about processes based on catchment rainfall‐runoff responses and physical controls.
The scale parameter β of PDC is more closely related to high precipitation, with the greater correlation with extreme precipitation (ρ = 0.9816 with 99 wet day percentile precipitation). The parameters of PDC and certain FDCs share similar spatial patterns but the parameters and shape of curves varies for different duration and interactions of the processes. The geographical characteristics such as properties of precipitation, BFI, Pmax*αp and CIM will influence the shape of PDC and FDCs.
•Comprehensive information of classification and physiological activity of biogenic amines.•Updated information on sample pretreatment and analytical methods of biogenic amines.•Separation ...conditions, analytical conditions and validation information are compared.•Abundant figures and tables are offered.
Biogenic amines (BAs), mainly produced by amino acid decarboxylation, are widespread in foods and human organisms. Appropriate intake of BAs is beneficial to the human body, while excessive consumption may cause discomfort. Meanwhile, BAs are a kind of chemical marker for evaluating meat freshness. For these reasons, simple, rapid and efficient methods have been developed for the determination of BAs in food and biological products. This review introduces the provenance, classification and physiological activity of eight essential BAs and summarizes the dominant pretreatment and analysis methods since 2010. Pretreatment technologies mainly include the “dilute and shoot” method, ultrasonic assisted extraction, solid-phase extraction, matrix solid-phase dispersion, dispersive liquid-liquid microextraction, etc. Determination methods include liquid chromatography coupled to ultraviolet or fluorescence detectors, liquid chromatography tandem mass spectrometry, capillary electrophoresis, biosensors and so on.
G-quadruplex (G4) structures formed by guanine-rich nucleic acids are implicated in essential physiological and pathological processes and serve as important drug targets. The genome-wide detection ...of G4s in living cells is important for exploring the functional role of G4s but has not yet been achieved due to the lack of a suitable G4 probe. Here we report an artificial 6.7 kDa G4 probe (G4P) protein that binds G4s with high affinity and specificity. We used it to capture G4s in living human, mouse, and chicken cells with the ChIP-Seq technique, yielding genome-wide landscape as well as details on the positions, frequencies, and sequence identities of G4 formation in these cells. Our results indicate that transcription is accompanied by a robust formation of G4s in genes. In human cells, we detected up to >123 000 G4P peaks, of which >1/3 had a fold increase of ≥5 and were present in >60% promoters and ∼70% genes. Being much smaller than a scFv antibody (27 kDa) or even a nanobody (12-15 kDa), we expect that the G4P may find diverse applications in biology, medicine, and molecular devices as a G4 affinity agent.
Electrolyte additive is an effective strategy to inhibit the uncontrolled growth of Li dendrites for lithium metal batteries (LMBs). However, most of the additives are complex synthesis and prone to ...decompose in cycling. Herein, in order to guide the homogeneous deposition of Li+, carbonized polymer dots (CPDs) as electrolyte additives are successfully designed and synthesized by microwave (M‐CPDs) and hydrothermal (H‐CPDs) approaches. The controllable functional groups containing N or O (especially pyridinic‐N, pyrrolic‐N, and carboxyl group) enable CPDs to keep stable in electrolytes for at least 3 months. Meanwhile, the clusters formed between CPDs and Li+ through electrostatic interaction effectively guide the uniform Li dispersion and limit the “tip effect” and dendrite formation. Moreover, as lithiophilic groups increase, the strong electrostatic interference for the solvation effect of Li+ in the electrolyte is formed, which induces faster Li+ diffusion/transfer. As expected, H‐CPDs achieve the ultra‐even Li+ transfer. The corresponding Li//LiFePO4 full cell delivers a high capacity retention rate of 93.8% after 200 cycles, which is much higher than that of the cells without additives (61.2%) and with M‐CPDs (83.7%) as additives. The strategy in this work provides a theoretical direction for CPDs as electrolyte additives used in energy storage devices.
Two kinds of carbonized polymer dots (CPDs) (M‐CPDs and H‐CPDs) as electrolyte additives are successfully designed and synthesized. H‐CPDs with more pyridinic‐N, pyrrolic‐N, and COOH deliver more even Li+ flux through abundant H‐CPDs‐Li clusters bound by strong electrostatic interaction. The symmetrical cell exhibits enhanced cycling stability of 3700 h.
Burnout is a stress-induced syndrome considered to be closely related to work. Although social support could relief burnout syndrome, its effect on learning burnout in medical students remains ...unclear. The objectives of the study are to evaluate the association between learning burnout and social support in Chinese medical students.
A cross-sectional online survey was distributed to students who participated in online learning in a medical college in Wuhan during the COVID-19 epidemic. We used the Lian version of the Maslach Burnout Inventory (MBI) to assess learning burnout and the Social Support Rating Scale (SSRS) to assess social support. Chi-square tests were used to analyze factors associated with burnout. Independent
-test and multiple logistic regression were explored to analyze the relationship between social support and burnout.
A total of 684 students have completed the survey (response rate: 30.9%), of which 315 (46.12%) met standard criteria for learning burnout. Multiple logistic regression analysis has revealed that seniors, low family income and low social support were significant predictors of learning burnout (χ
= 41.983,
< 0.001). After adjusting for the grade and family income, there was a significant and relevant association between social support and learning burnout (OR = 0.937; 95% CI: 0.905-0.970;
< 0.001).
Learning burnout was highly prevalent in medical students at our college. Senior students and low family income might be risk factors for learning burnout. Social support, especially subjective support and utilization of support might play a protective role in reducing the risk of learning burnout.
Human fingers possess stable high sensitivity and a wide range of tactile perception, attributed to the gradient microstructure and the interlocking collagen fiber on the skin's surface. However, ...challenges persist in achieving simultaneous enhancement of multiple functionalities in artificial skin. Inspired by the unique structure of the skin, a two‐step process involving ion diffusion‐induced and strong‐weak topological crosslinking is synergistically employed to fabricate a bilayer gradient hydrogel. Zn2+ initially diffuses to induce the formation of weak bonds, imparting elasticity. Subsequently, Fe3+/Zn2+ diffusion constructs a strong‐weak topologically crosslinked network, enhancing the toughness of the gel while reducing the brittleness associated with robust bonds. Due to its distinctive design, the gel employs an adaptive energy dissipation strategy subjected to large and small stress, ensuring high sensitivity (3.31 kPa−1, 0–2 kPa), wide sensing range (0.4–40.6 kPa), and exceptional stability (500 cycles). This flexible approach enables programmable design in three dimensions, including ion diffusion type, direction, and shape. This gel can detect the gentle brushing of feathers and human body movements. It utilizes significant differences generated by magnitudes of stress to perform binary information encryption. This study introduces a novel strategy for preparing skin‐like gels, offering promising potential for expanding their applications in complex scenarios.
The flexible network induced by weak Zn2+ diffusion undergoes simultaneous sacrifice and reconstruction when subjected to loading, endowing a bilayer gradient gel with high sensitivity. Through strong‐weak Fe3+/Zn2+ dual‐ion diffusion, a topological cross‐linked network is constructed, and the robust coordination imparts a wide detection range. Weak bonds, serving as a buffer, alleviate hysteresis induced by the fracture of brittle bonds.
Traditional artificial skin gels often only focuses on a single perspective and overlooks the necessity of multidimensional synergistic design for sensitivity enhancement. To address these problems, ...the innovative introduction of dual solvents on the surface of polyacrylamide/sodium alginate gel induces to the transformation of supramolecular interactions including ion coordination, crystalline alcohol, and phase separation, synergistically achieving adjustable wrinkle wavelengths (304.2 ± 19.9 to 2393.5 ± 95.9 µm) and modulated chemical compositions with tunable moduli (87.5 ± 3.3 to 157.6 ± 3.7 kPa). This flexible strategy allows the construction of long‐range ordered wrinkled microstructures of three‐dimensional surfaces and complex morphologies. Meanwhile, the bridge effect induced by crystalline alcohols directs the insertion of ethanol molecules into the polymer chains, effectively reducing intramolecular friction. Benefiting from the small wavelength and low modulus dominated by crystalline alcohol, the wrinkled gel exhibits extremely high sensitivity of 164 kPa−1 (<0.5 kPa) and wide detection range (44.3 kPa). The wrinkled gel remains stable high sensitive to detect micro‐ and large stress, tactile perception, and human motion behaviors. This work proposes a new strategy for constructing highly sensitive bioinspired skin from multiple dimensions, showing broad application prospects in the fields of bioengineering and behavioral cognition.
The bridge effect exhibited by dual solvent‐induced crystalline alcohols can effectively reduce the modulus of the hard shell and maintain a long‐range ordered wrinkled surface, synergistically achieving optimal sensitivity and wide detection range. Additionally, it facilitates the anchoring of ethanol within the gel system, leading to reduced intramolecular friction and improved stability.
Danshen: a phytochemical and pharmacological overview MEIm, Xiao-Dan; CAO, Yan-Feng; CHE, Yan-Yun ...
Chinese journal of natural medicines,
January 2019, 2019-Jan, 2019-01-00, 20190101, Letnik:
17, Številka:
1
Journal Article
Danshen, the dried root or rhizome of Salvia miltiorrhiza Bge., is a traditional and folk medicine in Asian countries, especially in China and Japan. In this review, we summarized the recent ...researches of Danshen in traditional uses and preparations, chemical constituents, pharmacological activities and side effects. A total of 201 compounds from Danshen have been reported, including lipophilic diterpenoids, water-soluble phenolic acids, and other constituents, which have showed various pharmacological activities, such as anti-inflammation, anti-oxidation, anti-tumor, anti-atherogenesis, and anti-diabetes. This article intends to provide novel insight information for further development of Danshen, which could be of great value to its improvement of utilization.
Pancreaticopleural fistula (PPF) is a very rare and critical complication of pancreatitis in children. The majority of publications relevant to PPF are case reports. No pooled analyses of PPF cases ...are available. Little is known about the pathogenesis and optimal therapeutic schedule. The purpose of this study was to identify the pathogenesis and optimal therapeutic schedule of PPF in children.
The patient was a 13-year-old girl who suffered from intermittent chest tightness and dyspnea for more than 3 months; she was found to have chronic pancreatitis complicated by PPF. The genetic screening revealed SPINK1 mutation. She was treated with endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic retrograde pancreatic drainage (ERPD); her symptoms improved dramatically after the procedures.
PPF is a rare pancreatic complication in children and causes significant pulmonary symptoms that can be misdiagnosed frequently. PPF in children is mainly associated with chronic pancreatitis (CP); therefore, we highlight the importance of genetic testing. Endoscopic treatment is recommended when conservative treatment is ineffective.
Epidemiological studies have investigated the relationship between infertility and the risk of ovarian cancer (OC); however, the results have been inconsistent. We therefore conducted the first ...meta‐analysis to update and quantify the aforementioned association based on prospective cohort studies. Studies were identified by searching PubMed, EMBASE and Web of Science databases up to January 8, 2020. We extracted data from the studies and performed quality assessments. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random‐effects model. Publication bias, and subgroup, meta‐regression and sensitivity analyses were also conducted. Nine prospective cohort studies with a total of 10 383 OC cases and 6 278 830 participants were included in the present study. The summary RR of the association between infertility and the risk of OC was 1.51 (95% CI: 1.35‐1.69), with low heterogeneity. Positive associations were observed in most subgroup analyses stratified by predefined factors, including region, duration of follow‐up, study quality, causes of infertility, invasiveness of OC, infertility treatment status and adjustment of potential confounding parameters. No significant publication bias was detected. Our findings suggest that infertility in women were associated with an increased risk of OC.
What's new?
To date, the epidemiological studies exploring the relationship between infertility and the risk of ovarian cancer have been inconclusive. For the first time, here the authors conducted a meta‐analysis of nine prospective cohort studies comprising 10 383 ovarian cancer cases and 6 278 830 participants. The findings suggest that infertility in women is associated with a 51% increased risk of ovarian cancer. Further studies are needed to disentangle the effects of specific causes of infertility in different histological subtypes of ovarian cancer.
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