In this work, a confined-doped fiber with the core/inner-cladding diameter of 40/250 μm and a relative doping ratio of 0.75 is fabricated through a modified chemical vapor deposition method combined with the chelate gas deposition technique, and subsequently applied in a tandem-pumped fiber amplifier for high-power operation and transverse mode instability (TMI) mitigation. Notably, the impacts of the seed laser power and mode purity are preliminarily investigated through comparative experiments. It is found that the TMI threshold could be significantly affected by the seed laser mode purity. The possible mechanism behind this phenomenon is proposed and revealed through comprehensive comparative experiments and theoretical analysis. Finally, a maximum output power of 7.49 kW is obtained with the beam quality factor of approximately 1.83, which is the highest output power ever reported in a forward tandem-pumped confined-doped fiber amplifier. This work could provide a good reference and practical solution to improve the TMI threshold and realize high-power high-brightness fiber lasers.

The selection of high-quality sperms is critical to intracytoplasmic sperm injection, which accounts for 70–80% of in vitro fertilization (IVF) treatments. So far, sperm screening is usually performed manually by clinicians. However, the performance of manual screening is limited in its objectivity, consistency, and efficiency. To overcome these limitations, we have developed a fast and noninvasive three-stage method to characterize morphology of freely swimming human sperms in bright-field microscopy images using deep learning models. Specifically, we use an object detection model to identify sperm heads, a classification model to select in-focus images, and a segmentation model to extract geometry of sperm heads and vacuoles. The models achieve an F1-score of 0.951 in sperm head detection, a z-position estimation error within ±1.5 μm in in-focus image selection, and a Dice score of 0.948 in sperm head segmentation, respectively. Customized lightweight architectures are used for the models to achieve real-time analysis of 200 frames per second. Comprehensive morphological parameters are calculated from sperm head geometry extracted by image segmentation. Overall, our method provides a reliable and efficient tool to assist clinicians in selecting high-quality sperms for successful IVF. It also demonstrates the effectiveness of deep learning in real-time analysis of live bright-field microscopy images.

Salicylic acid (SA), a phytohormone, has been considered to be a key regulator mediating plant defence against pathogens. It is still vague how SA activates plant defence against herbivores such as chewing and sucking pests. Here, we used an aphid-susceptible wheat variety to investigate Sitobion avenae response to SA-induced wheat plants, and the effects of exogenous SA on some defence enzymes and phenolics in the plant immune system. In SA-treated wheat seedlings, intrinsic rate of natural increase (rm), fecundity and apterous rate of S. avenae were 0.25, 31.4 nymphs/female and 64.4%, respectively, and significantly lower than that in the controls (P < 0.05). Moreover, the increased activities of phenylalanine-ammonia-lyase, polyphenol oxidase (PPO) and peroxidase in the SA-induced seedlings obviously depended on the sampling time, whereas activities of catalase and 4-coumarate:CoA ligase were suppressed significantly at 24, 48 and 72 h in comparison with the control. Dynamic levels of p-coumaric acid at 96 h, caffeic acid at 24 and 72 h and chlorogenic acid at 24, 48 and 96 h in wheat plants were significantly upregulated by exogenous SA application. Nevertheless, only caffeic acid content was positively correlated with PPO activity in SA-treated wheat seedlings (P = 0.031). These findings indicate that exogenous SA significantly enhanced the defence of aphid-susceptible wheat variety against aphids by regulating the plant immune system, and may prove a potential application of SA in aphid control.

In present study, we explored the effects and the underlying mechanisms of phospholipase C (PLC) mediating glucose-induced changes in intestinal glucose transport and lipid metabolism by using U-73122 (a PLC inhibitor). We found that glucose incubation activated the PLC signal and U-73122 pre-incubation alleviated the glucose-induced increase in plcb2, plce1 and plcg1 mRNA expression. Meanwhile, U-73122 pre-treatment blunted the glucose-induced increase in sodium/glucose co-transporters 1/2 mRNA and protein expressions. U-73122 pre-treatment alleviated the glucose-induced increase in TAG content, BODIPY 493/503 fluorescence intensity, lipogenic enzymes (glucose 6-phospate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), malic enzyme and fatty acid synthase (FAS)) activity and the mRNA expressions of lipogenic genes and related transcription factors (6pgd, g6pd, fas, acca, srebp1 and carbohydrate response element-binding protein (chrebp)) in intestinal epithelial cells of yellow catfish. Further research found that U-73122 pre-incubation mitigated the glucose-induced increase in the ChREBP protein expression and the acetylation level of ChREBP in HEK293T cells. Taken together, these data demonstrated that the PLC played a major role in the glucose-induced changes of glucose transport and lipid metabolism and provide a new perspective for revealing the molecular mechanism of glucose-induced changes of intestinal glucose absorption, lipid deposition and metabolism.

The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines recommend the Royal Free Hospital-Nutritional Prioritizing Tool (RFH-NPT) to identify malnutrition risk in patients with liver disease. However, little is known about the application of the RFH-NPT to screen for the risk of malnutrition in China, where patients primarily suffer from hepatitis virus-related cirrhosis. A total of 155 cirrhosis patients without liver cancer or uncontrolled co-morbid illness were enrolled in this prospective study. We administered the Nutritional Risk Screening 2002 (NRS-2002), RFH-NPT, Malnutrition Universal Screening Tool (MUST) and Liver Disease Undernutrition Screening Tool (LDUST) to the patients within 24 h after admission and performed follow-up observations for 1·5 years. The RFH-NPT and NRS-2002 had higher sensitivities (64·8 and 52·4 %) and specificities (60 and 70 %) than the other tools with regard to screening for malnutrition risk in cirrhotic patients. The prevalence of nutritional risk was higher under the use of the RFH-NPT against the NRS-2002 (63 v. 51 %). The RFH-NPT tended more easily to detect malnutrition risk in patients with advanced Child–Pugh classes (B and C) and lower Model for End-stage Liver Disease scores (<15) compared with NRS-2002. RFH-NPT score was an independent predictive factor for mortality. Patients identified as being at high malnutrition risk with the RFH-NPT had a higher mortality rate than those at low risk; the same result was not obtained with the NRS-2002. Therefore, we suggest that using the RFH-NPT improves the ability of clinicians to predict malnutrition risk in patients with cirrhosis primarily caused by hepatitis virus infection at an earlier stage.

For the guarantee of the long-distance transport of the bunches of China Initiative Accelerator Driven System (CIADS), a new scheme is proposed that extra magnetic field is used in the accelerator-target coupling section before the windowless target to minimize the self-modulation (SM) mechanism. Particle-in-cell simulations are carried out to study the influence of the solenoidal magnetic field on the self-modulation mechanism when long proton bunches move in the background plasmas. The long proton bunches used in the simulations are similar to these in the linear accelerator of CIADS. It is found that the presence of the solenoidal magnetic field will significantly inhibit the self-modulation process. For the strong magnetic field, the longitudinal separation and transverse focusing of the long bunches disappear. We attribute these phenomena to the reason that the strong solenoidal magnetic field restricts the transverse movement of plasma electrons. Thus, there are not enough electrons around the bunch to compensate the space charge effect. Moreover, without transverse current, the longitudinal pinched effect disappears, and the long bunch can not be separated into small pulses anymore.

Northeastern China is a region of high tick abundance, multiple tick-borne pathogens and likely human infections. The spectrum of diseases caused by tick-borne pathogens has not been objectively evaluated in this region for clinical management and for comparison with other regions globally where tick-transmitted diseases are common. Based on clinical symptoms, PCR, indirect immunofluorescent assay and (or) blood smear, we identified and described tick-borne diseases from patients with recent tick bite seen at Mudanjiang Forestry Central Hospital. From May 2010 to September 2011, 42% (75/180) of patients were diagnosed with a specific tick-borne disease, including Lyme borreliosis, tick-borne encephalitis, human granulocytic anaplasmosis, human babesiosis and spotted fever group rickettsiosis. When we compared clinical and laboratory features to identify factors that might discriminate tick-transmitted infections from those lacking that evidence, we revealed that erythema migrans and neurological manifestations were statistically significantly differently presented between those with and without documented aetiologies (P < 0.001, P = 0.003). Twelve patients (6.7%, 12/180) were co-infected with two tick-borne pathogens. We demonstrated the poor ability of clinicians to identify the specific tick-borne disease. In addition, it is necessary to develop specific laboratory assays for optimal diagnosis of tick-borne diseases.

Porous silicon nitride ceramics are attracting extensive attention due to its high strength and low dielectric loss. However, further strength enhancement at elevated temperatures is hindered by its intergranular phase, forming from sintering additives. This paper describes the fabrication of porous silicon nitride ceramic materials, by using a replacement method of carbothermal nitridation. The initial samples which were obtained from the sintering of mixed powder consisted of 95 wt% Si3N4 and 5 wt% Y2O3. After the removal of the oxide intergranular phase and the infiltration of mixtures of phenolic resins and silica sols, carbothermal nitridation process was carried out at 1550 °C for 2 h under nitrogen. X-ray diffraction and microstructural analysis revealed a complete replacement of oxide intergranular phases by the newly formed Si3N4 intergranular phase. The unmodified ceramic exhibited lower flexural strength at 1400 °C, which was only 50% of the room-temperature strength. Although the modified ceramic attained a slightly lower flexural strength at room temperature after the replacement of intergranular phase, its strength measured at 1400 °C could attain 90% of room-temperature strength.

On April 25, 2015, a massive 8.1-magnitude earthquake struck Nepal at 2:11 pm (Beijing time). The 68-member-strong China International Search & Rescue Team (CISAR) left for Nepal at 6 am, April 26, to help with relief work. The CISAR was the first foreign team to rescue a survivor who was trapped beneath the rubble in the Gongabu area after the earthquake. On May 8, the team fulfilled the search-and-rescue mission and returned to Beijing. During the 2 weeks of rescue work, the team treated more than 3700 victims and cleared approximately 430 buildings. In this rescue mission, 10 experienced medical officers (including nine doctors and a nurse) from the General Hospital of Chinese People’s Armed Police Force (PAP) comprised the medical team of CISAR. In this report, we focus on the medical rescues by CISAR and discuss the characteristics of the medical rescue in Nepal. (Disaster Med Public Health Preparedness. 2018;12:536–538)

Mycoplasma infections are most frequently associated with disease in the urogenital or respiratory tracts and, in most cases, mycoplasmas infect the host persistently. In HIV-infected individuals the prevalence and role of genital mycoplasmas has not been well studied. To investigate the six species of Mycoplasma and the risk factors for infection in Jiangsu province, first-void urine and venous blood samples were collected and epidemiological questionnaires were administered after informed consent. A total of 1541 HIV/AIDS patients were recruited in this study. The overall infection rates of six Mycoplasma species were: Ureaplasma urealyticum (26·7%), Mycoplasma hominis (25·3%), M. fermentans (5·1%), M. genitalium (20·1%), M. penetrans (1·6%) and M. pirum (15·4%). The Mycoplasma infection rate in the unmarried group was lower than that of the married, divorced and widowed groups [adjusted odds ratio (aOR) 1·432, 95% confidence interval (CI) 1·077–1·904, P < 0·05]. The patients who refused highly active antiretroviral therapy (HAART) had a much higher risk of Mucoplasma infection (aOR 1·357, 95% CI 1·097–1·679, P < 0·05). Otherwise, a high CD4+ T cell count was a protective factor against Mycoplasma infection (aOR 0·576, 95% CI 0·460–0·719, P < 0·05). Further research will be required to confirm a causal relationship and to identify risk factors for Mycoplasma infection in HIV/AIDS populations.

This paper aims to obtain an analytical expression for the ratio of unloading work of indentation (Wu) to total loading work of indentation (Wt) (work recovery ratio of indentation) in instrumented spherical indentation. The expanding cavity model and Lamé solution are used. Three typical stress–strain relations (elastic-perfectly plastic, linear hardening, and power-law hardening) are analyzed. The results of finite-element method coincide with the expressions. The expressions show that the work recovery ratio of indentation is just related to plastic parameters. Furthermore, elastic work (We) are obtained, and it is proved that We should be distinguished from Wu in spherical indentation.

Ab initio structure determination of new compound (Pb0.6Cu0.4)Sr2PrCu2O7−x was obtained at 300 and 100 K from X-ray powder diffraction data and refined by Rietveld technique. (Pb0.6Cu0.4)Sr2PrCu2O7−x has an isotypical structure with TlBa2CaCu2O7 (1212) at both 300 and 100 K. At 300 K, crystal data: (Pb0.522Cu0.4)Sr2PrCu206.53, Mr=681.293, tetragonal system, space group P4/lmmm, a = 3.8631(5)Å, c= 11.9134(2)Å, V= 177.79Å3, Z= 1, Dx, = 6.3631 g/cm3, μ=1036.549 cm−1 (λ=1.54051 Å), F(000) = 299.6, the structure was refined with 31 parameters to Rwp = 4.02%, Rp=2.96% for 3379 step intensities and Rb = 4.80%, Rf=5.17 for 143 reflections, “goodness of fit” S = 2.20. At 100 K, crystal data: (Pb0.547Cu0.4)Sr2PrCu2O6.89, Mr=692.232, tetragonal system, space group P4/mmm, a = 3.8580(2) Å, c= 11.8898(5) Å, Z=1, Dx = 6.4953 g/cm3, μ= 1053.235 cm−1 (λ=1.54051 Å), F(000) = 304.6, the structure was refined with 32 parameters to Rwp = 5.53%, Rp=4.22% for 2574 step intensities and Rb = 6.11%, Rf=5.31% for 111 reflection, “goodness of fit” S= 1.79. Moreover, the composition of Pb was refined to 0.522 at 300 K and to 0.547 at 100 K as compared with the stoichiometric composition 0.6.

The crystalline structure of new TlSr2PrCu207−x was obtained at room temperature (300 K) and low temperature (100 K) from X-ray powder diffraction with CuKα radiation using Rietveld analysis. TlSr2PrCu207−x has an isotypical structure with TlBa2CaCu207 (1212). At 300 K, crystal data: Tl0.864Sr2PrCu2O6.75, Mr=727.811, the tetragonal system, P4/mmm, a =3.85404(5) Å, c = 12.1046(2) Å, V=179.80 Å3, Z=1, Dx =6.7218 g cm−3, μ =1143.922 cm−1 (λ = 1.54051 Å), F(000)=317.0, the structure was refined with 28 parameters to Rwp=5.29%, Rp = 3.65% for 3551 step intensities and Rb=7.40%, Rf=639% for 155 peaks, “goodness of fit” 5=3.05. At 100 K, crystal data: Tl0.858Sr2PrCu2O6.61, Mr=724.345, the tetragonal system, P4/mmm, a =3.84872(6) Å, c = 12.0771(3) Å, V=178.89 Å3, Z=1, Dx=6.7235 g cm−3, μ=1146.939 cm−1 (λ= 1.54051 Å), F(000) = 315.4, the structure was refined with 26 parameters to Rwp=6.70%, Rp=5.11% for 2926 step intensities and Rb=7.83%, Rf=6.70% for 131 peaks, “goodness of fit” S = 1.75.