An approach for determination of lateral limit angle in kinematic planar sliding analysis for rock slopes

Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγlim.However,the assignment ofγlim is currently used generally based on an empirical criterion.This study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding block.The procedure to calculate this probability is introduced using the block theory method.It is found that the probability is correlated with the number of discontinuity sets presented in rock masses.Thus,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional method.Finally,an engineering case was used to compare the proposed and traditional kinematic analysis methods.The error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one.

Two-step growth of β-Ga_(2)O_(3) on c-plane sapphire using MOCVD for solar-blind photodetector

In this work,a two-step metal organic chemical vapor deposition(MOCVD)method was applied for growingβ-Ga_(2)O_(3) film on c-plane sapphire.Optimized buffer layer growth temperature(T_(B))was found at 700℃ and theβ-Ga_(2)O_(3) film with full width at half maximum(FWHM)of 0.66°was achieved.A metal−semiconductor−metal(MSM)solar-blind photodetector(PD)was fabricated based on theβ-Ga_(2)O_(3) film.Ultrahigh responsivity of 1422 A/W@254 nm and photo-to-dark current ratio(PDCR)of 10^(6) at 10 V bias were obtained.The detectivity of 2.5×10^(15) Jones proved that the photodetector has outstanding performance in detecting weak signals.Moreover,the photodetector exhibited superior wavelength selectivity with rejection ratio(R_(250 nm)/R_(400 nm))of 105.These results indicate that the two-step method is a promising approach for preparation of high-qualityβ-Ga_(2)O_(3)films for high-performance solar-blind photodetectors.

Risk factors and clinical significance of posterior slip of the proximal vertebral body after lower lumbar fusion

BACKGROUND Adjacent segment disease(ASD)after fusion surgery is frequently manifests as a cranial segment instability,disc herniation,spinal canal stenosis,spondylolisthesis or retrolisthesis.The risk factors and mechanisms of ASD have been widely discussed but never clearly defined.AIM To investigate the risk factors and clinical significance of retrograde movement of the proximal vertebral body after lower lumbar fusion.METHODS This was a retrospective analysis of the clinical data of patients who underwent transforaminal lumbar interbody fusion surgery between September 2015 and July 2021 and who were followed up for more than 2 years.Ninety-one patients with degenerative lumbar diseases were included(22 males and 69 females),with an average age of 52.3 years(40-73 years).According to whether there was retrograde movement of the adjacent vertebral body on postoperative X-rays,the patients were divided into retrograde and nonretrograde groups.The sagittal parameters of the spine and pelvis were evaluated before surgery,after surgery,and at the final follow-up.At the same time,the Oswestry Disability Index(ODI)and Visual Analogue Scale(VAS)were used to evaluate the patients’quality of life.RESULTS Nineteen patients(20.9%)who experienced retrograde movement of proximal adjacent segments were included in this study.The pelvic incidence(PI)of the patients in the retrograde group were significantly higher than those of the patients in the nonretrograde group before surgery,after surgery and at the final follow-up(P<0.05).There was no significant difference in lumbar lordosis(LL)between the two groups before the operation,but LL in the retrograde group was significantly greater than that in the nonretrograde group postoperatively and at the final follow-up.No significant differences were detected in terms of the|PI–LL|,and there was no significant difference in the preoperative lordosis distribution index(LDI)between the two groups.The LDIs of the retrograde group were 68.1%±11.5%and 67.2%±11.9%,respectively,which were significantly lower than those of the nonretrograde group(75.7%±10.4%and 74.3%±9.4%,respectively)(P<0.05).Moreover,the patients in the retrograde group had a greater incidence of a LDI<50%than those in the nonretrograde group(P<0.05).There were no significant differences in the ODI or VAS scores between the two groups before the operation,but the ODI and VAS scores in the retrograde group were significantly worse than those in the nonretrograde group after the operation and at the last follow-up,(P<0.05).CONCLUSION The incidence of posterior slippage after lower lumbar fusion was approximately 20.9%.The risk factors are related to a higher PI and distribution of lumbar lordosis.When a patient has a high PI and insufficient reconstruction of the lower lumbar spine,adjacent segment compensation via posterior vertebral body slippage is one of the factors that significantly affects surgical outcomes.

Effect of surgical timing on postoperative outcomes in patients with acute cholecystitis after delayed percutaneous transhepatic gallbladder drainage

BACKGROUND To date,the optimal timing for percutaneous transhepatic gallbladder drainage(PTGBD),particularly for patients who have missed the optimal window for emergency laparoscopic cholecystectomy(LC)(within 72 hours of symptom onset)has not been determined.AIM To study the effects of LC timing on outcomes of grade II/III acute cholecystitis(AC)in patients with delayed PTGBD.METHODS Data of patients diagnosed with Tokyo Guidelines 2018 grade II or III AC who underwent delayed PTGBD followed by LC at a single hospital between 2018 and 2022 were retrospectively studied.According to the interval between gallbladder drainage and cholecystectomy,the patients were divided into early and delayed LC groups.Outcomes including surgery time,postoperative complications and hospital stay,and patient satisfaction were analyzed and compared between the two groups using t-andχ^(2) tests.RESULTS There were no significant differences between the two groups in intraoperative blood loss,postoperative abdominal drainage tube placement time,pain index,or total disease duration(all P>0.05).Compared with those of the early LC group,the delayed group showed significant decreases in the length of procedure(surgery time),conversion rate to open surgery,degree of adhesions,surgical complications,postoperative hospital stay,and total treatment costs,and increased patient satisfaction despite a longer interval before PTGBD(all P<0.05).CONCLUSION For patients with grade II/III AC with delayed PTGBD,LC should be performed 2 weeks after PTGBD to decrease postoperative complications and hospital stays and improve patient satisfaction.

2009至2013年天津早产儿视网膜病变筛查分析（英文）

目的:分析天津地区早产儿视网膜病变(ROP)筛查的结果,研究肺表面活性剂及经鼻连续正压通气(NCPAP)对于ROP的影响。方法:多中心回顾性研究。2894例早产儿(1592男婴,1 302女婴)主要来自于天津市几家大型医院,筛查时间从2009-01/2013-12,对人口统计学信息,眼科检查结果和可能的全身危险因素均进行记录。孕周、出生体质量、吸氧、肺表面活性剂和NCPAP对ROP的影响进行了评估。结果:224例448眼患有ROP(7.7%)。其中,49例98眼为严重ROP。在对照组与ROP组之间呼吸窘迫综合征(RDS)、NCPAP、肺表面活性剂的应用差异有统计学意义(P<0.01)。Logistic回归分析结果表明小孕龄、低出生体质量、吸氧是导致ROP发生的危险因素。随着肺表面活性剂与NCPAP的使用率增加,吸氧率逐渐下降,ROP的发生率也在下降。结论:低出生体质量、低孕龄、吸氧史与ROP的发生密切相关,肺表面活性剂与NCPAP的使用可能是降低ROP发生的因素。

Optimization and Innovation of the Operation Model of Mobile Social E-commerce under AI Empowerment:Taking the Female Community Platform“Little Red Book”as an Example

This article takes the female community platform“Little Red Book”as an example to explore the optimization and innovation of mobile community e-commerce operation mode under Artificial Intelligence(AI)empowerment.Firstly,the relevant concepts were defined,and then the unique attributes of mobile community e-commerce were analyzed.As a typical representative of mobile community e-commerce,Little Red Book introduces the background and characteristics of its platform,analyzes its mobile community operation mode,and focuses on exploring how to establish a mobile community e-commerce platform and effective operation mode under the empowerment of AI technology,to provide some reference and inspiration for the development and operation of Little Red Book and other e-commerce platform enterprises.

食管静脉曲张套扎硬化序贯治疗的临床研究

目的研究食管静脉曲张内镜下硬化剂注射治疗(EIS)和套扎硬化序贯治疗(ELIS)的效果。方法对2013年11月-2017年5月在该院行内镜下治疗的126例肝硬化重度食管静脉曲张患者进行回顾性分析。按内镜下治疗方法将其分为两组,即EIS组和ELIS组。比较两组间治疗后72 h内再出血率、治疗后静脉曲张消失率、治疗后随访期限内静脉曲张复发率、治疗次数、硬化剂用量及其并发症发生率。结果 126例肝硬化重度食管静脉张患者EIS和ELIS治疗后总有效率分别为92.75%和98.25%,两组比较差异无统计学意义(P=0.150);随访期限内静脉曲张复发率分别为5.80%和10.52%,两组比较差异无统计学意义(P=0.328)。而在硬化剂用量及治疗次数方面,EIS和ELIS组分别为(69.12±9.45)和(38.45±13.39)ml以及(3.86±0.98)和(2.45±1.01)次,两组比较,差异均有统计学意义(P=0.000)。在72 h内再出血、急诊止血率、胸骨后疼痛、穿孔和狭窄等方面两组间比较,差异均无统计学意义。结论 EIS和ELIS治疗肝硬化门脉高压重度食管静脉曲张在疗效上无明显差异,但ELIS与EIS相比,可以明显减少硬化剂用量和治疗次数,可以彻底消除细碎的曲张静脉,阻断交通支,弥补单纯套扎治疗的不足,值得在临床推广。

骨外露创面扩创术修复后负压封闭引流联合局部氧疗的疗效及预后分析

目的探讨骨外露创面扩创术修复后给予负压封闭引流(VSD)联合局部氧疗的疗效及预后。方法选取2017年1月—2018年1月徐州市第一人民医院收治的88例行骨外露创面扩创修复术患者。按随机数字法分为VSD+氧疗组和机械治疗组。VSD+氧疗组行VSD联合局部氧疗,机械治疗组行传统清创联合换药方式治疗。比较两组创面愈合情况、临床治疗指标、创口微环境检测指标及不良反应情况。结果VSD+氧疗组临床基本愈合率较机械治疗组高(P<0.05)。VSD+氧疗组换药次数、完全愈合时间及住院时间较机械治疗组低(P<0.05)。两组渗液酸碱度、伤口温度及C反应蛋白比较,差异有统计学意义(P<0.05)。VSD+氧疗组不良反应率较机械治疗组低(P<0.05)。结论骨外露创面扩创术修复后给予VSD联合局部氧疗,能够改善创面愈合效果,改善创口微环境,提升临床治愈率和安全性。

Application of 16s rDNA Sequencing in the Analysis of Pathogenic Bacteria in Sputum of Severe Bacterial Pneumonia

Objective: 120 patients with severe pneumonia who were kept in the comprehensive ICU of our hospital in 2018 were selected, and 16s rDNA sequencing was performed to analyze the composition of pathogenic bacteria in the sputum of severe pneumonia. Methods: The sputum samples of patients with severe bacterial pneumonia were collected, and the diversity of pathogens in the samples was analyzed by polymerase chain reaction (PCR) amplification and high-throughput sequencing (16s rDNA PCR-DGGE). Results: Sequence showed that sputum samples contained a relatively large number of species, and there were many species that were not detected by sequencing. The dominant bacteria were Streptococcus, Sphingomonas, Corynebacterium, Denatobacteria, Aquobacteria, Acinetobacteria, Prevotella, Klebsiella, Pseudomonas, etc. Conclusion: Bacteria caused by sputum of severe bacterial pneumonia are complex and diverse, which provides new methods and ideas for individualized treatment of patients with severe pneumonia.

Application of 16S rDNA Sequencing Technology in the Analysis of Pathogenic Bacteria in Sputum of Severe Pneumonia

The diagnosis of pathogenic bacteria in severe pneumonia is difficult and the prognosis is poor. Its outcome is closely related to bacterial pathogenicity and the timeliness and pertinence of antibiotic treatment. Therefore, early diagnosis is of great significance to the prognosis of patients. Sputum examination and culture is the gold standard for the diagnosis of pathogens of severe pneumonia. However, due to the long time of bacterial culture, the early use of antibiotics, the change of bacteria species, mixed infection and other problems, the results of bacterial culture in sputum are often false negative. With the continuous application of new molecular biology techniques in clinical detection, the classification of bacteria and microorganisms has deepened from the identification of phenotypic characteristics to the classification of gene characteristics. Sequencing analysis with 16S rDNA sequencing technology has the characteristics of high sequencing flux, large amount of data obtained, short cycle, and can more comprehensively reflect the species composition of microbial community, real species distribution and abundance information. In this paper, 16S rDNA sequencing technology was used to analyze the bacterial population composition in the sputum of severe pneumonia, and to explore a new method of etiological diagnosis.

Laparoscopic VS open hepatectomy for hepatolithiasis: An updated systematic review and meta-analysis

AIM To perform a meta-analysis on laparoscopic hepatectomy VS conventional liver resection for treating hepatolithiasis.METHODS We conducted a systematic literature search on Pub Med,Embase,Web of Science and Cochrane Library,and undertook a meta-analysis to compare the efficacy and safety of laparoscopic hepatectomy V S conventional open liver resection for local hepatolithiasis in the left or right lobe. Intraoperative and postoperative outcomes(time,estimated blood loss,blood transfusion rate,postoperative intestinal function recovery time,length of hospital stay,postoperative complication rate,initial residual stone,final residual stone and stone recurrence) were analyzed systematically.RESULTS A comprehensive literature search retrieved 16 publications with a total of 1329 cases. Meta-analysis of these studies showed that the laparoscopic approach for hepatolithiasis was associated with significantly less intraoperative estimated blood loss [weighted mean difference(WMD): 61.56,95% confidence interval(CI): 14.91-108.20,P = 0.01],lower blood transfusion rate [odds ratio(OR): 0.41,95%CI: 0.22-0.79,P = 0.008],shorter intestinal function recovery time(WMD: 0.98,95%CI: 0.47-1.48,P = 0.01),lower total postoperative complication rate(OR: 0.52,95%CI: 0.39-0.70,P < 0.0001) and shorter stay in hospital(WMD: 3.32,95%CI: 2.32-4.32,P < 0.00001). In addition,our results showed no significant differences between the two groups in operative time(WMD: 21.49,95%CI: 0.27-43.24,P = 0.05),residual stones(OR: 0.79,95%CI: 0.50-1.25,P = 0.31) and stone recurrence(OR: 0.34,95%CI: 0.11-1.08,P = 0.07). Furthermore,with subgroups analysis,our results proved that the laparoscopic approach for hepatolithiasis in the left lateral lobe and left side could achieve satisfactory therapeutic effects. CONCLUSION The laparoscopic approach is safe and effective,with less intraoperative estimated blood loss,fewer postoperative complications,reduced length of hospital stay and shorter intestinal function recovery time than with conventional approaches.

Probabilistic assessment of tunnel convergence considering spatial variability in rock mass properties using interpolated autocorrelation and response surface method

This study aims at the probabilistic assessment of tunnel convergence considering the spatial variability in rock mass properties. The method of interpolated autocorrelation combined with finite difference analysis is adopted to model the spatial variability of rock mass properties. An iterative procedure using the first-order reliability method(FORM) and response surface method(RSM) is employed to compute the reliability index and its corresponding design point. The results indicate that the spatial variability considerably affects the computed reliability index. The probability of failure could be noticeably overestimated in the case where the spatial variability is neglected. The vertical scale of fluctuation has a much higher effect on the probabilistic result with respect to the tunnel convergence than the horizontal scale of fluctuation. And the influence of different spacing of control points on the computational accuracy is investigated.

Effect of notoginsenoside R1 on hepatic microcirculation disturbance induced by gut ischemia and reperfusion

AIM： To assess the effect of notoginsenoside R1 on hepatic microcirculatory disturbance induced by gut ischemia/reperfusion （I/R） in mice. METHODS： The superior mesenteric artery （SMA） of C57/BL mice was ligated for 15 min to induce gut ischemia followed by 30-rain reperfusion. In another set of experiments, R1 was continuously infused （10 mg/kg per hour） from 10 min before I/R until the end of the investigation to study the influence of R1 on hepatic microcirculatory disturbance induced by gut I/R. Hepatic microcirculation was observed by inverted microscopy, and the vascular diameter, red blood cell （RBC） velocity and sinusoid perfusion were estimated. Leukocyte rolling and adhesion were observed under a laser confocal microscope. Thirty and 60 min after reperfusion, lactate dehydrogenase （LDH）, alanine aminotransferase （ALl＇） and aspartate transaminase （AST） in peripheral blood were determined. The expression of adhesion molecules CD11b/CD18 in neutrophils and tumor necrosis factor- alpha （TNF-α）, interleukin-6 （IL-6） and monocyte chemotactic protein-1 （MCP-1） in plasma were evaluated by flow Oltometry. E-selectin and intercellular adhesion molecule-1 （ICAM-1） in hepatic tissue were examined by immunofluorescence.RESULTS： After gut I/R, the diameters of terminal portal venules and central veins, RBC velocity and the number of perfused sinusoids were decreased, while the leukocyte rolling and adhesion, the expression of E-selectin in hepatic vessels and CD18 in neutrophils, IL-6, MCP-1, LDH, ALT and AST were increased. R1 treatment attenuated these alterations except for IL-6 and MCP-1. CONCLUSION： R1 prevents I/R-induced hepatic microcirculation disturbance and hepatocyte injury, The effect of R1 is related to its inhibition of leukocyte rolling and adhesion by inhibiting the expression of E-selectin in endothelium and CD18 in neutrophils.

A universal elliptical disc(UED)model to represent natural rock fractures

Since natural fractures are often non-equidimensional,the circular disc model still has great limitations.By contrast,the elliptical disc model is more applicable to representing natural fractures,especially for slender ones.This paper developed a universal elliptical disc(UED)model by incorporating the center point,size,and azimuth of fractures as variables.Specifically,with respect to the azimuth of elliptical fractures in three-dimensional(3D)space,we proposed a paradigm to construct its probability density function(PDF)by coupling the orientation and rotation angle of long axis based on three coordinate transformations.To illustrate the construction process of the PDF of the fracture azimuth,we took the orientation following the Fisher distribution and the rotation angle following Von Mises distribution as an example.A rock slope is used to show the use of the developed UED model,and the 3D DFNs for the slope rock mass are generated by Monte Carlo simulation.In addition,the DFNs for the rock mass are also generated based on the existing circular disc model and non-universal elliptical disc model.The comparison results from the three models clearly illustrate the superiority of the UED model over the existing circular and non-universal elliptical disc models.

Petrogenesis and tectonic implications of Indosinian granitoids from Western Qinling Orogen,China:Products of magma-mixing and fractionation

The Western Qinling Orogen(WQO) is characterized by voluminous distribution of Indosinian granitoids,the formation of which provides an important window to unravel the geochemical and geodynamic evolution and associated metallogeny.Here we investigate a group of intrusions termed "Five Golden Flowers" based on petrological,geochemical,zircon U-Pb geochronological and Lu-Hf isotopic studies on the granitoids and their mafic microgranular enclaves(MMEs).Our results show that these intrusions are genetically divided into two types,namely,magma-mixing and highly fractionated.The Jiaochangba,Lujing,Zhongchuan,and Luchuba granitoids are biotite monzogranites(220±0.8 Ma to 217±2.6 Ma) with abundant coeval MMEs(220±.1 Ma to 217±2.7 Ma).The rocks contain moderate to high SiO2,high MgO,Rb,Sr,Ba,and Th contents,but low TiO2,P2 O5,and Sc values,A/CNK of <1.1,and a range of εHf(t) values of-11.7 to +2.23 with corresponding TDM2values of 1967-1228 Ma.The MMEs possess K-feldspar megacrysts,abundant acicular apatites,and show lopsided textures.They have lower SiO2,Al2 O3,and Th contents,but higher MgO,TiO2,and Sc,with εHf(t) values of-18.0 to +3.18 and TDM1 of 849-720 Ma.The data indicate that the MMEs were derived from a magma sourced from the enriched lithospheric mantle.We suggest that these host granitoids were produced by partial melting of latePaleoproterozoic to early-Mesoproterozoic lower crust with the involvement of Neoproterozoic SCLM-derived mafic magmas.The Baijiazhuang pluton is dominantly composed of leucogranite(muscovite granite and twomica monzogranite,216±1.5 Ma) without MMEs.The rocks are peraluminous with high A/CNK(1.06-1.27).Compared with the other four granitoids,the Baijiazhuang leucogranite shows higher SiO2 content,markedly lower concentrations of TiO2,MgO,Al2 O3,CaO,and Fe2 O3T,and lower LREE/HREE and(La/Yb)N values.These leucogranites are also rich in Rb,Th,and U,and display marked depletions in Ba,Sr,Ti,and Eu,indicating that they experienced significant fractionation.Zircon εHf(t) values(-10.2 to-3.27) and TDM2(1868-1424 Ma),as well as the Nb/Ta and K2 O/Na2 O values are similar to the other four granitoids,indicating that they are likely to have been derived from a similar source;with sediments playing only a minor role in the magma generation.The low contents of Yb and Y suggest that their partial melting was controlled by garnets and micrographic texture of K-feldspar reflects high-temperature melting through undercooling.Based on the above features,we infer that the Baijiazhuang leucogranite likely represents the product of high degree fractionation of the I-type biotite monzogranite magma which generated the other four granitoids at relatively high temperatures,within magma chambers at mid-crust depths.We propose that the granitoid suite was formed in the transitional setting from synto post-collision during the collisional orogeny between the SCB and NCB,following break-off of the subducted South China Block lithosphere during 220-216 Ma.

Risk factors of metabolic syndrome after liver transplantation

BACKGROUND： Liver transplantation is a treatment of choice for both acute and chronic liver failure. Accompanied with the increase of long-term survival rates of recipients, metabolic syndrome and its individual components, including obesity, hyperglycemia, hypertension and hyperlipidemia, have become more frequent post liver transplantation. Here we reviewed the literature concerning the risk factors for the development of metabolic complications in liver recipients.

Mechanism underlying the protective effect of Kaixin Jieyu Fang on vascular depression following cerebral white matter damage

The Chinese compound Kaixin fieyu Fang can be used to treat vascular depression; however, the underlying mechanism remains unclear. This study established a rat model of chronic cerebral ischemia-caused white matter damage by ligation of the bilateral common carotid arteries. Rats received daily intragastric administration of a suspension of Kaixin ]ieyu Fang powder. After 3, 7 and 21 days of treatment, the degree of white matter damage in the cerebral ischemia rat model was alleviated, Bcl-2 protein and mRNA expression in brain tissue increased, and Bax protein and mRNA expression decreased. These results indicate that Kaixin Jieyu Fang can alleviate cere- bral white matter damage, and the underlying mechanism is associated with regulation of Bcl-2/ Bax protein and mRNA expression, which is one of possible mechanism behind the protective effect of Kaixin Jieyu Fang against vascular depression.

QTL analysis across multiple environments reveals promising chromosome regions associated with yield-related traits in maize under drought conditions

Drought is one of the most critical abiotic stresses influencing maize yield. Improving maize cultivars with drought tolerance using marker-assisted selection requires a better understanding of its genetic basis. In this study, a doubled haploid(DH) population consisting of 217 lines was created by crossing the inbred lines Han 21(drought-tolerant) and Ye 478(drought-sensitive). The population was genotyped with a 6 K SNP assay and 756 SNP(single nucleotide polymorphism) markers were used to construct a linkage map with a length of 1344 c M. Grain yield(GY), ear setting percentage(ESP), and anthesis–silking interval(ASI) were recorded in seven environments under well-watered(WW) and water-stressed(WS) regimes. High phenotypic variation was observed for all traits under both water regimes. Using the LSMEAN(least-squares mean) values from all environments for each trait, 18 QTL were detected, with 9 associated with the WW and 9 with the WS regime. Four chromosome regions,Chr. 3: 219.8–223.7 Mb, Chr. 5: 191.5–194.7 Mb, Chr. 7: 132.2–135.6 Mb, and Chr. 10: 88.2–89.4 Mb, harbored at least 2 QTL in each region, and QTL co-located in a region inherited favorable alleles from the same parent. A set of 64 drought-tolerant BC_3F_6 lines showed preferential accumulation of the favorable alleles in these four regions, supporting an association between the four regions and maize drought tolerance. QTL-by-environment interaction analysis revealed 28 ed QTL(environment-dependent QTL) associated with the WS regime and 22 associated with the WW regime for GY, ESP, and ASI. All WS QTL and55.6% of WW QTL were located in the ed QTL regions. The hotspot genomic regions identified in this work will support further fine mapping and marker-assisted breeding of drought-tolerant maize.

Positional cloning of PmCH1357 reveals the origin and allelic variation of the Pm2 gene for powdery mildew resistance in wheat

Powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici(Bgt), is a prevalent disease in common wheat(Triticum aestivum L.) and causes serious yield losses worldwide. We used a map-based approach to clone the major broad-spectrum powdery mildew resistance gene Pm CH1357 from wheat breeding line CH1357. Pm CH1357 was mapped to a 526 kb region containing only Traes CS5 D01 G044600. The Traes CS5 D01 G044600 sequence of the susceptibility allele in Taichung 29(TC29) was identical to that in Chinese Spring, whereas the sequence of the resistance allele in CH1357 was identical to Pm2a previously cloned from the germplasm Ulka/*8Cc. The susceptibility allele in TC29 contained a 7 bp deletion in exon 1, resulting in loss of 856 of the 1277 amino acids in the predicted nucleotide-binding domain leucine-rich repeat containing Pm2a protein.Pm CH1357/Pm2a sequence was also isolated from the Chinese wheat landraces and cultivars that were previously reported to possess the resistance gene Pm2b, Pm2c,PmLX66, or PmND399. The Pm CH1357/Pm2a resistance allele was present in 10 of 495 accessions in core germplasm and contemporary cultivars from China and the USA. A newly developed diagnostic marker for the 7 bp In Del in the resistance gene can be used to eliminate the susceptibility allele in wheat breeding programs.

High performance silicon-based GeSn p–i–n photodetectors for short-wave infrared application

An investigation of germanium-tin(GeSn) on silicon p–i–n photodetectors with a high-quality Ge0.94 Sn0.06 absorbing layer is reported. The Ge Sn photodetector reached a responsivity as high as 0.45 A/W at the wavelength of 1550 nm and 0.12 A/W at the wavelength of 2 μm. A cycle annealing technology was applied to improve the quality of the epitaxial layer during the growth process by molecular beam epitaxy. A low dark-current density under 1 V reverse bias about 0.078 A/cm2 was achieved at room temperature. Furthermore, the Ge Sn photodetector could detect a wide spectrum region and the cutoff wavelength reached to about 2.3 μm. This work has great importance in silicon-based short-wave infrared detection.