Performance Limits and Advancements in Single 2D Transition Metal Dichalcogenide Transistor

Two-dimensional(2D)transition metal dichalcogenides(TMDs)allow for atomic-scale manipulation,challenging the conventional limitations of semiconductor materials.This capability may overcome the short-channel effect,sparking significant advancements in electronic devices that utilize 2D TMDs.Exploring the dimension and performance limits of transistors based on 2D TMDs has gained substantial importance.This review provides a comprehensive investigation into these limits of the single 2D-TMD transistor.It delves into the impacts of miniaturization,including the reduction of channel length,gate length,source/drain contact length,and dielectric thickness on transistor operation and performance.In addition,this review provides a detailed analysis of performance parameters such as source/drain contact resistance,subthreshold swing,hysteresis loop,carrier mobility,on/off ratio,and the development of p-type and single logic transistors.This review details the two logical expressions of the single 2D-TMD logic transistor,including current and voltage.It also emphasizes the role of 2D TMD-based transistors as memory devices,focusing on enhancing memory operation speed,endurance,data retention,and extinction ratio,as well as reducing energy consumption in memory devices functioning as artificial synapses.This review demonstrates the two calculating methods for dynamic energy consumption of 2D synaptic devices.This review not only summarizes the current state of the art in this field but also highlights potential future research directions and applications.It underscores the anticipated challenges,opportunities,and potential solutions in navigating the dimension and performance boundaries of 2D transistors.

Neural Network-Based State Estimation for Nonlinear Systems With Denial-of-Service Attack Under Try-Once-Discard Protocol

Dear Editor,This letter deals with state estimation issues of discrete-time nonlinear systems subject to denial-of-service(DoS)attacks under the try-once-discard(TOD)protocol.More specifically,to reduce the communication burden,a TOD protocol with novel update rules on protocol weights is designed for scheduling measurement outputs.In addition,unknown nonlinear functions vulnerable to DoS attacks are considered due to the openness and vulnerability of the network.

Dissecting the genetic architecture of glucosinolate compounds for quality improvement in flowering stalk tissues of Brassica napus

Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.

The characteristics of mRNA m^(6)A methylomes in allopolyploid Brassica napus and its diploid progenitors

Genome duplication events,comprising whole-genome duplication and single-gene duplication,produce a complex genomic context leading to multiple levels of genetic changes.However,the characteristics of m^(6)A modification,the most widespread internal eukaryotic mRNA modification,in polyploid species are still poorly understood.This study revealed the characteristics of m^(6)A methylomes within the early formation and following the evolution of allopolyploid Brassica napus.We found a complex relationship between m^(6)A modification abundance and gene expression level depending on the degree of enrichment or presence/absence of m^(6)A modification.Overall,the m^(6)A genes had lower gene expression levels than the non-m^(6)A genes.Allopolyploidization may change the expression divergence of duplicated gene pairs with identical m^(6)A patterns and diverged m^(6)A patterns.Compared with duplicated genes,singletons with a higher evolutionary rate exhibited higher m^(6)A modification.Five kinds of duplicated genes exhibited distinct distributions of m^(6)A modifications in transcripts and gene expression level.In particular,tandem duplication-derived genes showed unique m^(6)A modification enrichment around the transcript start site.Active histone modifications(H3K27ac and H3K4me3)but not DNA methylation were enriched around genes of m^(6)A peaks.These findings provide a new understanding of the features of m 6A modification and gene expression regulation in allopolyploid plants with sophisticated genomic architecture.

Effects of V-pits covering layer position on the optoelectronic performance of InGaN green LEDs

The impact of the V-pits covering layer(VCL) position on the optoelectronic performance of InGaN-based green light-emitting diodes(LEDs) was investigated. It is found that earlier covering of V-pits will hinder the hole injection via the sidewall of V-pits, and then result in less quantum wells(QWs) participating in radioluminescence. The current-voltage characteristics show that the LEDs with earlier covering of V-pits have higher operating voltage at room temperature, and a more dramatic voltage rise with the reduction of temperature. Meanwhile, more manifested emission peaks for sidewall QWs and deeper QWs near to ntype layer was observed in the sample with earlier coveing of V-pits at cryogenic temperatures, for the reason that the holes being injected via V-pits sidewall have higher kinetic energy and could transport to deeper QWs.

Estimation of chlorophyll content in Brassica napus based on unmanned aerial vehicle images

The chlorophyll content has a direct effect on photosynthesis of crops.In order to explore a quick and convenient method for estimating the chlorophyll content of Brassica napus and facilitate efficient crop monitoring,we measured the actual value of chlorophyll with a SPAD-502 chlorophyll detector,and collected aerial images of B.napus with an unmanned aerial vehicle(UAV)carrying a RGB camera in this study.The total number of 270samples collected images were divided into regions according to the planting conditions of different B.napus varieties in the field.Then,according to the empirical formula,there were 36 colors’characteristic parameters calculated and combined.To estimate the chlorophyll content of rape,189 samples were included in the modeling set,while the other 81 samples were enrolled in the validation set for testing the accuracy of this model.After the combination of R(red),G(green)and B(blue)color channels,the results showed that the color characteristics B/(R+G),b,B/G,(G-B)/(G+B),g-b were highly connected with the measured value of chlorophyll SPAD,and the correlation coefficient between the combination based on B/(R+G)and SPAD value was 0.747.With R2=0.805,RMSE=3.343,and RE=6.84%,the regression model created using random forest had superior outcomes,according to the model comparison.This study offers a new method for quickly estimating the amount of chlorophyll in rapeseed and a workable reference for crop monitoring using the UAV platform.

A preliminary report on adjuvant analgesic efficacy of HANS in opioid tolerant patients with cancer pain

Objective： To observe the adjuvant analgesic efficacy of Han＇s Acupoint Nerve Stimulator （HANS） in opioid tolerant patients with cancer pain. Methods： A prospective non-controlled study was conducted. Opioid tolerant patients with cancer pain were enrolled and treated with both routinely analgesics and adjuvant HANS （2/100 Hz for 30 min/d, 5 d on and 2 d off for two weeks）. Cancer pain, quality of life （QOL）, anxiety and depression were assessed before enrollment and on d 8 and d 15 with the BPI-C, EORTC QLQ-C30, and self-rating anxiety scale （SAS）/ self-rating depression scale （SDS）, respectively; the therapeutic frequency of breakthrough pain （BP） and daily opioid dose were also recorded. Results： Totally 47 patients meeting the inclusion criteria participated in this study; 43 patients completed the two-week treatment and assessment. The mean scores of patient＇s ＂worst＂ and ＂least＂ pain intensity assessed with BPI-C decreased significantly on d 8 and d 15; the therapeutic frequency of BP also significantly decreased; but the average daily dose of opioids did not change significantly. For the nine symptoms in EORTC QLQ-C30 assessment, the mean scores of pain, fatigue, constipation and insomnia were significantly lower on d 8 and d 15 compared with baseline; the mean scores of the overall health status, nausea/vomiting and the incidence rates of both anxiety and depression also decreased significantly on d 15. Conclusions： To opioid tolerant patients with cancer pain, adjuvant treatment with HANS could improve pain release and patients＇ QOL by decreasing the severity of pain, fatigue, constipation, insomnia and other concomitant symptoms; it could also decrease the incidence rates of anxiety and depression.

p53 mutation regulates PKD genes and results in co-occurrence of PKD and tumorigenesis

Objective: Polycystic kidney disease(PKD) is the major cause of kidney failure and mortality in humans. It has always been suspected that the development of cystic kidney disease shares features with tumorigenesis, although the evidence is unclear.Methods: We crossed p53 mutant mice(p53N236S, p53S) with Werner syndrome mice and analyzed the pathological phenotypes.The RNA-seq, ss GSEA analysis, and real-time PCR were performed to dissect the gene signatures involved in the development of disease phenotypes.Results: We found enlarged kidneys with fluid-filled cysts in offspring mice with a genotype of G3mTerc^(-/-)WRN^(-/-)p53^(S/S)(G3TM).Pathology analysis confirmed the occurrence of PKD, and it was highly correlated with the incidence of tumorigenesis. RNA-seq data revealed the gene signatures involved in PKD development, and demonstrated that PKD and tumorigenesis shared common pathways, including complement pathways, lipid metabolism, mitochondria energy homeostasis and others. Interestingly, this G3TM PKD and the classical PKD1/2 deficient PKD shared common pathways, possibly because the mutant p53S could regulate the expression levels of PKD1/2, Pkhd1, and Hnf1b.Conclusions: We established a dual mouse model for PKD and tumorigenesis derived from abnormal cellular proliferation and telomere dysfunction. The innovative point of our study is to report PKD occurring in conjunction with tumorigenesis. The gene signatures revealed might shed new light on the pathogenesis of PKD, and provide new molecular biomarkers for clinical diagnosis and prognosis.

Transcriptome analysis reveals genes expression pattern of seed response to heat stress in Brassica napus L.

Seeds might deteriorate,and lose the ability to germinate when stored under high temperature and high humidity.Brassica napus is one of the most important oil crops in China.However,B.napus seeds were generally stored through summer season with high ambient temperature,which lead to seed viability loss.In order to understand the mechanism of seed response to heat stress and improve seed heat tolerance,B.napus seeds were treated with high temperature(40℃)and ultra-high temperature(60℃)for 4 h.The germination of heatstressed seeds were obviously slower,the germination index and vigor index decreased with temperature increase from 40 to 60℃,and the 40℃ pretreatment could improve the seed tolerance to 60℃ heat stress.Transcriptomics results showed that 442 differentially expressed genes(DEGs)were identified in seeds after heat stress.Gene ontology and KEGG pathway enrichment analysis revealed that some of the genes were involved in posttranslational modification,protein turnover,chaperones and carbohydrate transport,metabolic pathways and secondary metabolites biosynthesis pathway.Among these DEGs,sHSP and transcription factors genes were involved in heat stress tolerance.Thirty-two overlapping genes under different high temperature stress(40℃ and 60℃)were enriched in biological processes of response to oxidative stress and abiotic stimulus.The expression trends of 12 genes randomly selected from the RNA-seq data were almost consistent with the results of qRT-PCR.Our results revealed several potential candidate genes and pathways related to heat responsive by high temperature,which is beneficial for further improving the heat tolerance in B.napus seeds.

Pay attention to the rehabilitation of cancer patients—Excerpts of the 2013 NCCN Guidelines for Survivorship

For some survivors, the consequences of cancer are minimal; these patients can return to a normal life after the completion of treatment. In fact, a majority of cancer survivors report being in good general health and experience good to excellent quality of life. A recent review suggests that at least 50% of survivors suffer from some late effects of cancer treatment. The most common problems in cancer survivors are depression, pain, and fatigue. The guidelines suggest the following standards for survivorship care:(1) prevention of new and recurrent cancers and other late effects;(2) surveillance for cancer spread, recurrence, or second cancers;(3) assessment of late psychosocial and medical effects;(4) intervention for consequences of cancer and treatment(eg, medical problems, symptoms, psychologic distress, financial and social concerns); and(5) coordination of care between primary care providers and specialists to ensure that all of the survivor's health needs are met. The NCCN Survivorship Panel hopes that these guidelines can help both oncologic and primary health care professionals lessen the burden left on survivors by their cancer experience so they can transition back to a rewarding life.

Analysis of cancer pain in hospitals in Beijing,China

Objective:This study aimed to survey the characteristics and treatments of cancer pain in Beijing hospitals,China.Methods:At 20:00 on December 22,2009,there conducted a questionnaire survey in 2238 patients with malignant tumors of 26 hospitals in Beijing,and the survey results were statistically analyzed.Results:The 531 cases in 2238 patients had pained and 121 cases (22.79%) had outbreak pain with one week.At 20:00 on December 22,2009,199 cases (38%) in the above-mentioned 531 pain patients suffered the moderate to severe pain (pain scores ≥ 4).The number of pain (pain scores ≥ 4) patients in the consecutive three days from December 20 to December 22 were 150.Conclusion:In the 531 cancer pain patients of the surveyed hospitals,38% of the patients were not satisfied with the pain control.Doctors believed that the main reason for pain not controlled was the non-standard treatment,but patients considered to be afraid of addiction.

Mechanistic study of angiogenesis induced by <i>shh</i>-transfected BMMSC transplantation after myocardial infarction

Objective: To investigate the changes and mechanism of angiogenesis in myocardium induced by transplantation of the sonic hedgehog (shh) gene transfected in bone marrow mesenchymal stem cells (BMMSC) after myocardial infarction. Methods: A rat model of acute myocardial infarction was made by coronary artery ligation. The rats were randomly divided into five groups of 40 rats each. These were further subdivided into groups of 10 rats. The peripheral regions of the infarcts were injected with either BMMSCSHH (transfection group), equivalent BMMSC (cell only group), BMMSC and pcDNA3.1-Shh DNA mixture (mixture group), pcDNA3.1-shh DNA alone (gene only group), or equal volumes of low-sugar DMEM medium (control group). One, two, four, and eight weeks after transplantation, specimens were harvested from the transplantation site to determine the expression of SHH signaling pathway downstream genes Ptc1, Gli-2, COUP-TF II, angiogenesis promoting factor VEGF, and Ang-1 using RT-PCR. Results: Seven days after transplantation, the expression of SHH signaling pathway downstream genes, Ptc1, Gli-2, and COUP-TF II was significantly more pronounced in the transfection group than in the control group, cell only group, gene only group, or mixture group (Ptc1: P P P < 0.05, and P COUP-TF II: P P P P Gli-2: P P P < 0.05, and P < 0.05, respectively). The expression of angiogenesis-promoting genes Vegf and Ang-1 was significantly more pronounced than in the control group, cell only group, or gene only group (Vegf: P P P Ang-1: P P P < 0.05, respectively). Conclusion: Transplantation of the shh-gene-transfected BMMSCs to the peripheral regions of myocardial infarcts promoted angiogenesis by upregulating downstream gene expression.

Identi cation of seed heat tolerance and its correlation with agronomic traits in Brassica napus L.

To better understand the effect of high temperature on seed viability, artificial aging treatments were implemented on 472 accessions of rapeseed (Brassica napus L.) by constant high temperature at 70℃for 8h. Results showed a remarkable impact of constant heat on seed germination. After heat treatment, considerable variation was found in seed germinability, some genotypes even lost the ability to germinate. The effect of accelerated aging was highly significant. Germination parameters varied among ecotypes. Seed viability varied with different origin, and was significantly and positively correlated with seed yield per plant and dry weight of aboveground parts per plant among 14 agronomic traits. Germination traits were positively correlated with oil contents.

Comparison between SSR and SNP systems of genetic diversity analysis in Brassica napus L.

Simple sequence repeat(SSR) capillary electrophoresis and single nucleotide polymorphism(SNP) array are widely used tools for investigating genetic diversity. However, efficiency between SSR and SNP on rapeseed genetic diversity has not been systematically assessed yet. In this study, both SSR and SNP were used on 446 worldwide B. napus germplasm lines. Data shows that 65 pairs of primers(70 SSRs) and 250 SNPs were necessary to identify the similar accessions. Furthermore, no significant differences were found between 2 systems on basic statistics, population structures, principal components and kinship parameters. In general, either SSR or SNP is efficient for genetic diversity estimation. However, our data revealed the fact that SNP array system shows slightly more accuracy than SSR system on ecotype groups division.

1,4-硼氮杂芳烃在中国的研究进展

稠环芳烃及其衍生物在有机光电材料领域具有广泛应用,杂原子掺杂可有效调节稠环芳烃的物理化学性质.硼氮杂芳烃是稠环芳烃的重要成员.基于硼原子和氮原子的相对位置,硼氮杂芳烃可以分为三种异构体:1,2-硼氮杂芳烃、1,3-硼氮杂芳烃和1,4-硼氮杂芳烃,由于合成上的困难,1,3-硼氮杂芳烃的研究相对较少.近年来,得益于1,4-硼氮杂芳烃在多重共振热活化延迟荧光材料方面潜力的发掘,1,4-硼氮杂芳烃在国内外都取得了飞速发展.我国有机化学及材料化学领域的学者们积极参与并推动了1,4-硼氮杂芳烃的快速发展,在1,4-硼氮杂芳烃的结构开发和应用拓展方面开展了一系列原创性的工作,取得了瞩目的成绩.以1,4-硼氮芳烃的结构作为线索,按照杂原子二元掺杂(B/N)骨架和三元掺杂(X/B/N)骨架分别进行论述,综述了1,4-硼氮杂芳烃的合成发展历史和应用研究拓展,最后对硼氮杂芳烃领域的未来发展与应用进行了展望.

有晶状体眼虹膜固定型人工晶状体植入术后再手术原因及安全性

目的:探讨有晶状体眼虹膜固定型人工晶状体(PIOL)植入术后再手术原因以及长期眼内植入的安全性。方法:回顾性系列病例研究。选择2006年1月至2016年12月于青岛眼科医院白内障科接受有晶状体眼虹膜固定型PIOL植入术治疗高度近视后接受再次眼内手术治疗的患者11例(17眼)。分析再次手术的时间、方式以及原因。数据采用配对t检验进行分析。结果:再次手术的时间为PIOL植入术后6~108个月。12眼(12/17)因为外伤导致PIOL脱位于前房而接受了再次手术,该12眼再手术前角膜内皮细胞计数与植入术前比较,出现不同程度下降(t=5.968,P<0.001),其中1眼因脱位时间较长(1个月)而最终出现角膜内皮细胞功能失代偿。另有2眼(2/17)虽未出现PIOL脱位,但由于PIOL所夹虹膜较少或部分萎缩,PIOL位置松动,角膜内皮细胞非预期性明显减少,从而接受了人工晶状体再固定术;1眼(1/17)因为对侧眼PIOL脱位,角膜内皮细胞计数下降明显,患者出于恐慌,而决定手术取出PIOL;1例(1眼)患者(1/17)因为PIOL植入后出现视网膜脱离接受了视网膜复位手术,由于术后长期俯卧位,对侧眼(1/17)角膜内皮细胞计数下降明显(658个/mm2)而接受PIOL再固定手术。结论:外伤后PIOL脱位,PIOL松动后非预期性角膜内皮细胞计数下降是有晶状体眼虹膜固定型PIOL植入术后再次手术的主要原因。对于长期植入的患者需增加随访排查潜在的安全隐患。

Si-substrate vertical-structure InGaN/GaN micro-LED-based photodetector for beyond 10 Gbps visible light communication

Visible light communication(VLC)has emerged as a promising communication method in 6G.However,the development of receiving devices is much slower than that of transmitting devices,limited by materials,structures,and fabrication.In this paper,we propose and fabricate an InGaN/GaN multiple-quantum-well-based vertical-structure micro-LED-based photodetector(μPD)on a Si substrate.A comprehensive comparison of the photoelectrical performance and communication performance of three sizes ofμPDs,10,50,and 100μm,is presented.The peak responsivity of all threeμPDs is achieved at 400 nm,while the passband full-widths at half maxima are 87,72,and 78 nm for 10,50,and 100μmμPDs,respectively.The−20 dB cutoff bandwidth is up to 822 MHz for 50μmμPD.A data rate of 10.14 Gbps is experimentally demonstrated by bit and power loading discrete multitone modulation and the proposed digital pre-equalizer algorithm over 1 m free space utilizing the self-designed 4×450μmμPD array as a receiver and a 450 nm laser diode as a transmitter.This is the first time a more than 10 Gbps VLC system has been achieved utilizing a GaN-based micro-PD,to the best of our knowledge.The investigation fully demonstrates the superiority of Si substrates and vertical structures in InGaN/GaNμPDs and shows its great potential for high-speed VLC links beyond 10 Gbps.

Efficient emission of InGaN-based light-emitting diodes:toward orange and red

Indium gallium nitride(InGaN)-based light-emitting diodes(LEDs)are considered a promising candidate for red-green-blue(RGB)micro displays.Currently,the blue and green LEDs are efficient,while the red ones are inefficient for such applications.This paper reports our work of creating efficient InGaN-based orange and red LEDs on silicon(111)substrates at low current density.Based on the structure of InGaN yellow LEDs,by simply reducing the growth temperature of all the yellow quantum wells(QWs),we obtained 599 nm orange LEDs with peak wall-plug efficiency(WPE)of 18.1%at 2 A/cm^2.An optimized QW structure was proposed that changed two of the nine yellow QWs to orange ones.Compared with the sample containing nine orange QWs,the sample with two orange QWs and seven yellow QWs showed similar emission spectra but a much higher peak WPE up to 24.0%at 0.8 A/cm^2 with a wavelength of 608 nm.The improvement of peak WPE can be attributed to the improved QW quality and the reduced active recombination volume.Subsequently,a series of efficient InGaN-based orange and red LEDs was demonstrated.With further development,the InGaN-based red LEDs are believed to be attainable and can be used in micro LED displays.

Efficient InGaN-based yellow-light-emitting diodes

Realization of efficient yellow-light-emitting diodes(LEDs) has always been a challenge in solid-state lighting.Great effort has been made, but only slight advancements have occurred in the past few decades. After comprehensive work on InGaN-based yellow LEDs on Si substrate, we successfully made a breakthrough and pushed the wall-plug efficiency of 565-nm-yellow LEDs to 24.3% at 20 A∕cm^2 and 33.7% at 3 A∕cm^2. The success of yellow LEDs can be credited to the improved material quality and reduced compressive strain of InGaN quantum wells by a prestrained layer and substrate, as well as enhanced hole injection by a 3 D pn junction with V-pits.

Ag_(2)Se Complex Nanostructures with Photocatalytic Activity and Superhydrophobicity

Single-crystalline Ag_(2)Se complex nanostructures have been synthesized via a solvothermal route in which selenophene(C4H4Se)as a selenylation source reacts with AgNO3 at a temperature of 240°C.An orthorhombic phaseβ-Ag_(2)Se nanostructure was identified by X-ray diffraction(XRD),Raman spectroscopy,field emission scanning electron microscopy(FE-SEM),high resolution transmission electron microscopy(HRTEM),and photoluminescence(PL)spectroscopy.The wettability of the as-synthesizedβ-Ag_(2)Se nanostructure was studied by measurement of the water contact angle(CA).Static water CA values of over 150°were obtained,which can be attributed to theβ-Ag_(2)Se complex nanostructure having a combination of micro-and nanostructures.The superhydrophobic Ag_(2)Se nanostructure may find applications in self-cleaning.Additionally,the photocatalytic activity of the as-synthesizedβ-Ag_(2)Se nanostructure was evaluated by photodegradation of rhodamine B(RhB)dye under ultraviolet(UV)light irradiation.