小叶黄杨的化学成分及心肌细胞保护作用研究

研究小叶黄杨(Buxus sinica var.parvifolia M.Cheng)叶子的化学成分及心肌细胞保护作用。综合运用硅胶、Sephadex LH-20、MCI、半制备液相等多种色谱分离方法,对小叶黄杨中等极性部位进行分离纯化,采用波谱学技术对分离的单体化合物进行结构鉴定。另外,对提取各部位和分离得到的14个化合物进行体外心肌细胞保护作用测试。从小叶黄杨干燥叶中共分离得到14个化合物,分别为香草酸乙酯(1)、香草醛(2)、花椒毒素(3)、反式对羟基肉桂酸乙酯(4)、3,4,5-trimethoxycinnamyl alcohol(5)、丁香酸乙酯(6)、(S)-5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5 H)-one(7)、桦木酸(8)、4-羟基-3,5-二甲氧基苯甲醛(9)、7,3′,4′-三甲基槲皮素(10)、白桦脂醇(11)、penduletin(12)、23-O-(E)-p-coumaroyl-23-hydroxybetulin(13)、松脂素(14)。其中化合物2、5和6为首次从该植物中分离得到,体外实验表明EA部位和化合物14(松脂素)可显著改善H_(2)O_(2)诱导的心肌细胞损伤。

Interface optimization and defects suppression via Na F introduction enable efficient flexible Sb_(2)Se_(3) thin-film solar cells

Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications.

Study on GC-MS fingerprint of petroleum ether fraction of Shenqi Jiangtang Granules

Objective To establish gas chromatography-mass spectrometry(GC-MS)fingerprint method for the petroleum ether fraction of Shenqi Jiangtang Granules(SQJTG)and evaluate the product quality.Methods The GC-MS fingerprint of petroleum ether fraction of SQJTG was established by GC-MS,and the chemical components corresponding to the fingerprint peaks were structurally identified on NIST2014.The batch consistency of SQJTG products was evaluated based on the chemical composition of petroleum ether parts by using fingerprint similarity evaluation and Principal components analysis(PCA)technology.At the same time,Hotelling's T2 and DMODX statistics are used to set the control range for the quality of different batches of products.Results Twenty-two components were identified from the petroleum ether part of SQJTG,accounting for 60.94%of the total components separated.The similarity of fingerprints of petroleum ether parts of 24 batches of SQJTG was greater than 0.95.The PCA of 24 batches of samples were all under the control limits of Hotellin’s T2 and DMODX statistics,indicating that the petroleum ether parts of different batches of SQJTG were consistent.Conclusion The developed GC-MS fingerprint method can be used to evaluate the quality of SQJTG.

Antimicrobial and Antioxidant Activities of Methanolic Extract and Fractions of <i>Epilobium roseum</i>(Schreb.) against Bacterial Strains

Present study aims to evaluate antimicrobial and antioxidant activities of the crude methanolic extract and different fractions of the Epilobium roseum (Schreb). The extract and fractions were used against pathogenic bacteria (Bacillus subtilis, Bacillus atrophaeus, Klebsiella pneumonia and Pseudomonas aeruginosa) and fungal strains (Aspergillus niger and Aspergillus flavus). The methanolic extract and their sub fraction n-hexane showed a prominent inhibition zone against all bacterial strains but inactive against fungal strains. The various extracts of Epilobium roseum (Schreb) from various parts were tested for their antioxidant activity by 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) assay. The IC50 of the stem and root of methanolic extract and their sub fraction n-hexane showed best activity ranged between 22.73 ± 6.92, 21.49 ± 6.26 and 14.94 ± 3.54, 13.92 ± 1.04 μg/ml compared to another fraction. The results support that Epilobium roseum can be used as antimicrobial and antioxidant agents. The results support the present study that Epilobium roseum (Schreb) has a potential source of natural antibacterial, antifungal and antioxidant potentials.

Genetic Variation among Seedling of Pumpkins Genotypes through SDS-Page

Genetic diversity in 30 genotypes of Pumpkins was collected from unexplored mountainous areas of Khyber Pakhtunkhwa, Pakistan was investigated through biochemical characterization. For biochemical characterization, Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis was carried out. The seed proteins were resolved on 7.5% and 15% polyacrylamide gel. A total of 35% genetic disagreement was observed in the collected lines with linkage distances ranging from 0.00 - 0.83 (percent disagreement). Similarly, cluster analysis sorted total germplasm on the basis of 12 bands (total bands) into eight clusters. Present study revealed a considerable amount of genetic diversity explored in pumpkin germplasm, Cluster analysis exhibited moderate level of genetic diversity;to broaden the gene pool. Further collection of the important germplasm is needed to be used in the development of improved cultivars with respect to quality and quantity.

Low-Dimensional Halide Perovskites and Their Advanced Optoelectronic Applications

Metal halide perovskites are crystalline materials originally developed out of scientific curiosity. They have shown great potential as active materials in optoelectronic applications. In the last 6 years, their certified photovoltaic efficiencies have reached 22.1%. Compared to bulk halide perovskites, low-dimensional ones exhibited novel physical properties. The photoluminescence quantum yields of perovskite quantum dots are close to 100%. The external quantum efficiencies and current efficiencies of perovskite quantum dot light-emitting diodes have reached 8% and 43 cd A^(-1),respectively, and their nanowire lasers show ultralow-threshold room-temperature lasing with emission tunability and ease of synthesis. Perovskite nanowire photodetectors reached a responsivity of 10 A W^(-1)and a specific normalized detectivity of the order of 10^(12 )Jones. Different from most reported reviews focusing on photovoltaic applications, we summarize the rapid progress in the study of low-dimensional perovskite materials, as well as their promising applications in optoelectronic devices. In particular, we review the wide tunability of fabrication methods and the state-of-the-art research outputs of low-dimensional perovskite optoelectronic devices. Finally, the anticipated challenges and potential for this exciting research are proposed.

Recent progress and perspectives on Sb_(2)Se_(3)-based photocathodes for solar hydrogen production via photoelectrochemical water splitting

Photoelectrochemical(PEC) cells involved with semiconductor electrodes can simultaneously absorb solar energy and perform chemical reactions, which are considered as an attractive strategy to produce renewable and clean hydrogen energy. Sb_(2)Se_(3) has been widely investigated in constructing PEC photocathodes benefitting of its low toxicity, suitable band gap, superior optoelectronic properties, and outstanding photocorrosion stability. We first present a brief overview of basic concepts and principles of PEC water splitting as well as a comparison between Sb_(2)Se_(3) and other numerous candidates. Then the material characteristics and preparation methods of Sb_(2)Se_(3) are introduced. The development of Sb_(2)Se_(3)-based photocathodes in PEC water splitting with various architectures and engineering efforts(i.e., absorber engineering, interfaces engineering, co-catalyst engineering and tandem engineering) to improve solar-to-hydrogen(STH) efficiency are highlighted. Finally, we debate the possible future directions to further explore the researching fields of Sb_(2)Se_(3)-based photocathodes with a strongly positive outlook in PEC processed solar hydrogen production.

金缕半枫荷乙酸乙酯部位化学成分研究

目的研究金缕半枫荷茎枝乙酸乙酯提取部位的化学成分。方法采用硅胶、Sephadex LH-20柱色谱、高效液相色谱(HPLC)、高效液相制备色谱等将乙酸乙酯部位进行分离和纯化,波谱法鉴定化合物结构。对半枫荷总提、各提取部位和分离得到的14个化合物进行抗氧化活性测试。结果鉴定出14个化合物,分别为:肉豆蔻酸(1)、硬脂酸(2)、芝麻素(3)、9-十八碳烯酸(4)、亚油酸(5)、邻苯二甲酸二丁酯(6)、豆甾醇(7)、β-谷甾醇(8)、羽扇豆醇(9)、齐墩果酸(10)、lup-20(29)-ene-3-[3-keto-hexadecanoate](11)、防葵素(12)、C-藜芦酰乙二醇(13)、2,3-二羟基-1-(4-羟基-3,5-二甲氧基苯基)-1-丙酮(14)。结论首次通过分离手段从该植物的茎枝中得到11个化合物,分别为1、3-7、9、11-14,并且体外抗氧化实验表明半枫荷乙酸乙酯部位、分离纯化得到的化合物13和14抗氧化活性较强。

High-efficiency ultra-thin Cu_(2)ZnSnS_(4) solar cells by double-pressure sputtering with spark plasma sintered quaternary target

In recent years,Cu_(2)ZnSnS_(4)(CZTS)semiconductor materials have received intensive attention in the field of thin-film solar cells owing to its non-toxic and low-cost elements.In this work,double-pressure sputtering technology is applied to obtain highly efficient and ultra-thin(-450 nm)pure Cu_(2)ZnSnS_(4)(CZTS)solar cell.Using mixed materials with sulfides and copper powder as a quaternary target via spark plasma sintering(SPS)method and adopting double-layer sputtering(high+low pressure),a highly adhesive and large-grained CZTS thin film is achieved.As a result,the damage to the surface of Mo contact is decreased so that the reflectivity of incident light can be improved.Moreover,the composition of CZTS film was more uniform and the secondary phase separation at the Mo interface was reduced.Therefore,the interface defect state and deep level defect density in corresponding device with double-pressure is reduced and the ratio of depletion thickness to absorption layer thickness can reached to 0.58,which promoted the collection of photogenerated carriers.Finally,an efficiency of 9.3%for ultra-thin(~450 nm)CZTS film solar cell is obtained.

Back contact interfacial modification mechanism in highly-efficient antimony selenide thin-film solar cells

Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several years.The properties of Sb_(2)Se_(3)absorber and back contact influence the PV performances of Sb_(2)Se_(3)solar cells.Hence,optimization of back contact characteristics and absorber orientation are crucial steps in raising the power conversion efficiency(PCE)of Sb_(2)Se_(3)solar cells.In this work,MoO2was introduced as an intermediate layer(IL)in Sb_(2)Se_(3)solar cells,and comparative investigations were conducted.The growth of(211)-oriented Sb_(2)Se_(3)with large grains was facilitated by introducing the MoO2IL with suitable thickness.The MoO2IL substantially lowered the back contact barrier and prevented the formation of voids at the back contact,which reduced the thickness of the MoSe2interface layer,inhibited carrier recombination,and minimized bulk and interfacial defects in devices.Subsequently,significant optimization enhanced the open-circuit voltage(VOC)of solar cells from 0.481 V to 0.487 V,short-circuit current density(JSC)from 23.81 m A/cm^(2)to 29.29 m A/cm^(2),and fill factor from 50.28%to 57.10%,which boosted the PCE from 5.75%to 8.14%.

Forkhead box P3 and indoleamine 2,3-dioxygenase co-expression in Pakistani triple negative breast cancer patients

BACKGROUND Forkhead box P3(FOXP3)is a specific marker for immunosuppressive regulatory T(T-reg)cells.T-regs and an immunosuppressive enzyme,indoleamine 2,3-dioxygenase(IDO),are associated with advanced disease in cancer.AIM To evaluate the co-expression of FOXP3 and IDO in triple negative breast cancer(TNBC)with respect to hormone-positive breast cancer patients from Pakistan.METHODS Immunohistochemistry was performed to analyze the expression of FOXP3,IDO,estrogen receptor,progesterone receptor,and human epidermal growth factor receptor on tissues of breast cancer patients(n=100):Hormone-positive breast cancer(n=51)and TNBC(n=49).A total of 100 patients were characterized as FOXP3 negative vs positive and further categorized based on low,medium,and high IDO expression score.Univariate and multivariate logistic regression models were used.RESULTS Out of 100 breast tumors,25%expressed FOXP3 positive T-regs.A significant coexpression of FOXP3 and IDO was observed among patients with TNBC(P=0.01)compared to those with hormone-positive breast cancer.Two variables were identified as significant independent risk factors for FOXP3 positive:IDO expression high(adjusted odds ratio(AOR)5.90;95%confidence interval(CI):1.22-28.64;P=0.03)and TNBC(AOR 2.80;95%CI:0.96-7.95;P=0.05).CONCLUSION Our data showed that FOXP3 positive cells might be associated with high expression of IDO in TNBC patients.FOXP3 and IDO co-expression may also suggest its involvement in disease,and evaluation of FOXP3 and IDO expression in TNBC patients may offer a new therapeutic option.

TC-Net:A Modest&Lightweight Emotion Recognition System Using Temporal Convolution Network

Speech signals play an essential role in communication and provide an efficient way to exchange information between humans and machines.Speech Emotion Recognition(SER)is one of the critical sources for human evaluation,which is applicable in many real-world applications such as healthcare,call centers,robotics,safety,and virtual reality.This work developed a novel TCN-based emotion recognition system using speech signals through a spatial-temporal convolution network to recognize the speaker’s emotional state.The authors designed a Temporal Convolutional Network(TCN)core block to recognize long-term dependencies in speech signals and then feed these temporal cues to a dense network to fuse the spatial features and recognize global information for final classification.The proposed network extracts valid sequential cues automatically from speech signals,which performed better than state-of-the-art(SOTA)and traditional machine learning algorithms.Results of the proposed method show a high recognition rate compared with SOTAmethods.The final unweighted accuracy of 80.84%,and 92.31%,for interactive emotional dyadic motion captures(IEMOCAP)and berlin emotional dataset(EMO-DB),indicate the robustness and efficiency of the designed model.

Robust Counting in Overcrowded Scenes Using Batch-Free Normalized Deep ConvNet

The analysis of overcrowded areas is essential for flow monitoring,assembly control,and security.Crowd counting’s primary goal is to calculate the population in a given region,which requires real-time analysis of congested scenes for prompt reactionary actions.The crowd is always unexpected,and the benchmarked available datasets have a lot of variation,which limits the trained models’performance on unseen test data.In this paper,we proposed an end-to-end deep neural network that takes an input image and generates a density map of a crowd scene.The proposed model consists of encoder and decoder networks comprising batch-free normalization layers known as evolving normalization(EvoNorm).This allows our network to be generalized for unseen data because EvoNorm is not using statistics from the training samples.The decoder network uses dilated 2D convolutional layers to provide large receptive fields and fewer parameters,which enables real-time processing and solves the density drift problem due to its large receptive field.Five benchmark datasets are used in this study to assess the proposed model,resulting in the conclusion that it outperforms conventional models.

Research on Phase-Shifted Full-Bridge Circuit Based on Frequency and Phase-Shift Synthesis Modulation Strategy

The full-bridge converters usually use transformer leakage inductance and parallel resonant capacitors to achieve smooth current commutation and soft switching functions,which can easily cause problems such as energy leakage and significant duty cycle loss.This paper designs a novel full-bridge zero-current(FB-ZCS)converter with series resonant capacitors and proposes a frequency and phase-shift synthesis modulation(FPSSM)control strategy based on this topology.Compared with the traditional parallel resonant capacitor circuit,the passive components used are significantly reduced,the structure is simple,and there is only a slight energy loss.By controlling the charging time of the capacitor,it can be achieved without additional switches or auxiliary circuits.The automatic control of capacitor energy based on input current addresses the low efficiency of the traditional control strategies.This paper introduces its principle in detail and verifies it through simulation.Finally,an experimental prototype was built further to demonstrate the feasibility of the theory through experiments.The module can be applied to a photovoltaic DC collection system using input parallel output series(IPOS)cascade to provide a new topology for large-scale,long-distance DC transmission.

Ins and outs of Helicobacter pylori association with autoimmune rheumatic diseases

Helicobacter pylori(H.pylori) infection is widely prevalent throughout worldwide.H.pylori manage a long-term survival in hostile environment of human stomach leading to peptic ulcer diseases and gastric cancer.But mostly infected person remains asymptomatic.Its chronic interaction with immune system makes H.pylori as an attractive candidate for the researchers to study its association with autoimmune diseases.This article presents a review of the literature on the association of H.pylori infection in selective autoimmune rheumatic diseases(RD).The authors used Me SH terms "Helicobacter pylori " with "rheumatoid arthritis," "systemic lupus erythematosus," or "fibromyalgia" to search Pub Med database.All relevant studies identified were included.Despite extensive medical advancement many questions on role of H.pylori infection in autoimmune RD still remain unanswered.Further studies are therefore needed to address the role of H.pylori in pathogenesis of RD.

Lentinus squarrosulus an edible macro-fungus reported from Pakistan

Lentinus squarrosulus(Mont.)Singer:an edible macro-fungus is reported from the moist temperate Himalayan forests of Pakistan.The sample was studied based on morphological characteristics and nucleotide sequence analyses of the ITS region.Studies based on morpho-anatomical and molecular data are consistent with formerly reported specimens.Lentinus squarrosulus represents the first report for Pakistan.

Depositional and Bio-Sequence Stratigraphic Framework of Late Cretaceous Kawagarh Formation,Kala-Chitta Range,Pakistan:Equivalent of Gurpi Formation(Iran)

The present study is focused on evaluation of deep marine pelagic sediments of Late Cretaceous Kawagarh Formation of Kala-Chitta Range in the context of microfacies analysis,paleoenvironmental interpretation,planktonic foraminiferal biostratigraphy,sequence stratigraphy and diversification of species.A total of thirty three rock samples were collected from the measured section.Three microfacies are interpreted,namely planktonic foraminifera wackestone,planktonic foraminifera mudstone and sandy mudstone indicating low energy depositional environment i.e.,outer ramp.The biostratigraphic studies show plentiful planktonic foraminifera species of Globotruncana,Heterohelix and Globotruncanita.However,no association of benthic or siliceous organisms was observed.On the basis of available species assemblage,a single local planktonic foraminifera biozone i.e.,Globotruncana-Heterohelix-Globotruncanita Assemblage Biozone is established.The biozone information is combined with published literature and Lower Santonian to Middle Maastrichtian age has been assigned to the Kawagarh Formation.The trend of species occurrences evinces that species number decreases over time with pulsated rise in the Kawagarh Formation.The Kawagarh Formation carbonates show an overall Transgressive Systems Tract(TST).The Kawagarh Formation of Pakistan evinces analogous characteristics to that of the Late Cretaceous Gurpi Formation of Iran based on the geologic age,outcrop lithology,microfacies,planktonic foraminiferal assemblages,depositional setting and sequence stratigraphy.

Carrier recombination suppression and transport enhancement enable high-performance self-powered broadband Sb_(2)Se_(3) photodetectors

Antimony selenide(Sb_(2)Se_(3))is a promising candidate for photodetector applications boasting unique material benefits and remarkable optoelectronic properties.Achieving high-performance self-powered Sb_(2)Se_(3)photodetector through a synergistic regulation of absorber layer and heterojunction interface demonstrates great potential and needs essential investigation.In this study,an effective two-step thermodynamic/kinetic deposition technique containing sputtered and selenized Sb precursor is implemented to induce self-assembled growth of Sb_(2)Se_(3)light absorbing thin film with large crystal grains and desirable[hk1]orientation,presenting considerable thin-film photodetector performance.Furthermore,aluminum(Al^(3+))cation dopant is introduced to modify the optoelectronic properties of CdS buffer layer,and further optimize the Sb_(2)Se_(3)/CdS(Al)heterojunction interface quality.Thanks to the suppressed carrier recombination and enhanced carrier transport kinetics,the champion Mo/Sb_(2)Se_(3)/CdS(Al)/ITO/Ag photodetector exhibits self-powered and broadband characteristics,accompanied by simultaneously high responsivity of 0.9 A W^(-1)(at 11 nW cm^(-2)),linear dynamic range of 120 dB,impressive ON/OFF switching ratio over 10^(6)and signal-to-noise ratio of 10^(9),record total noise determined realistic detectivity of 4.78×10^(12)Jones,and ultra-fast response speed with rise/decay time of 24/75 ns,representing the top level for Sb_(2)Se_(3)-based photodetectors.This intriguing work opens up an avenue for its selfpowered broadband photodetector applications.

Applications of beneficial plant growth promoting rhizobacteria and mycorrhizae in rhizosphere and plant growth:A review

Because of climate change and the highly growing world population,it becomes a huge challenge to feed the whole population.To overcome this challenge and increase the crop yield,a large number of fertilizers are applied but these have many side effects.Instead of these,scientists have discovered beneficial rhizobacteria,which are environmentally friendly and may increase crop yield and plant growth.The microbial population of the rhizosphere shows a pivotal role in plant development by inducing its physiology.Plant depends upon the valuable interactions among the roots and microbes for the growth,nutrients availability,growth promotion,disease suppression and other important roles for plants.Recently numerous secrets of microbes in the rhizosphere have been revealed due to huge development in molecular and microscopic technologies.This review illustrated and discussed the current knowledge on the development,maintenance,interactions of rhizobacterial populations and various proposed mechanisms normally used by PGPR in the rhizosphere that encouraging the plant growth and alleviating the stress conditions.In addition,this research reviewed the role of single and combination of PGPR,mycorrhizal fungi in plant development and modulation of the stress as well as factors affecting the microbiome in the rhizosphere.

Lexsegment Ideals Are Sequentially Cohen-Macaulay

The associated primes of an arbitrary lexsegment ideal I C S = K[x1,..., xn] are determined. As application it is shown that S/I is a pretty clean module, therefore S/I is sequentially Cohen-Mazaulay and satisfies Stanley＇s conjecture.