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Patients with adolescent idiopathic scoliosis suffer severe health issues. The unclear dynamic biomechanical characteristics of scoliosis were needed to be explored to improve the prevention and treatment in clinics. Validated 3D finite element (FE) models of thoracolumbosacral spine (T1-S1) both with and without scoliosis were developed from computed tomography (CT) images. Modal and harmonic analyses were performed to investigate the biomechanical responses of the spinal models to vibration. Resonant frequencies of the scoliotic model were lower than those of the model without scoliosis. Peak amplitudes occurred at vibrational frequencies close to the modal resonant frequencies, which caused the deformed thoracic segment in scoliosis suffered the maximum amplitude. The stresses on vertebrae and intervertebral discs in the scoliotic model derived from vibrations were significantly larger than those in the non-scoliosis model, and heterogeneously concentrated on the scoliotic thoracic segment. In conclusion, the scoliotic spine in the patients with Lenke 1BN scoliosis is more prone to injuries than the non-scoliotic spine while vibrating. Scoliotic thoracic segments in patients with Lenke 1BN scoliosis were the more vulnerable and sensitive component of the T1-S1 spine to vibration than lumbar spines. This study suggested that vibration would impair the scoliotic spines, and patients with Lenke 1BN scoliosis should avoid exposure to vibration, especially the low-frequency vibration.

Anxiety and depressive disorders are closely associated; however, the pathophysiology of these disorders remains poorly understood. Further exploration of the mechanisms involved in anxiety and depression such as the stress response may provide new knowledge that will contribute to our understanding of these disorders. Fifty-eight 8–12-week-old C57BL6 mice were separated into experimental groups by sex as follows: male controls (n = 14), male restraint stress (n = 14), female controls (n = 15) and female restraint stress (n = 15). These mice were taken through a 4-week randomised chronic restraint stress protocol, and their behaviour, as well as tryptophan metabolism and synaptic proteins, were measured in the prefrontal cortex and hippocampus. Adrenal catecholamine regulation was also measured. The female mice showed greater anxiety-like behaviour than their male counterparts. Tryptophan metabolism was unaffected by stress, but some basal sex characteristics were noted. Synaptic proteins were reduced in the hippocampus in stressed females but increased in the prefrontal cortex of all female mice. These changes were not found in any males. Finally, the stressed female mice showed increased catecholamine biosynthesis capability, but this effect was not found in males. Future studies in animal models should consider these sex differences when evaluating mechanisms related to chronic stress and depression.

Most Alzheimer disease (AD) patients present as sporadic late onset AD, with metabolic factors playing an important role in the occurrence and development of AD. Given the link between peripheral insulin resistance and tau pathology in streptozotocin-injected and db/db mouse models of diabetes, we fed high fat diet (HFD) to pR5 mice expressing P301L mutant human tau, with the aim of developing a new model with characteristics of obesity, T2DM and AD to mimic AD patients exacerbated by obesity and T2DM, an increasing trend in modern society. In our study, pR5 and C57BL/6 (WT) mice were randomly allocated to a standard diet (STD) or HFD for 30 weeks starting at 8 weeks of age. Food intake was measured weekly, body weight and fasting glucose levels were measured fortnightly, and a comprehensive behavioral test battery was performed to assess anxiety, depression and cognitive dysfunction. Glucose and insulin tolerance tests were performed after 30 weeks of HFD. We also investigated the effect of long term HFD on tau pathology in the brains of WT and P301L mice by performing western blotting of whole brain homogenates for total tau, phosphorylated tau at Ser396 and Thr231. Our results show that pR5 mice fed with HFD are more vulnerable to diet induced obesity compared to WT, especially with increasing age. In addition, pR5 mice on HFD developed glucose intolerance and insulin resistance. It was identified that long term HFD significantly aggravates depression like behavior and impairs cognitive function in pR5 mice, and also induces anxiety like behavior in both pR5 and WT mice. Long term HFD was also shown to aggravate tau hyperphosphorylation in pR5 transgenic mice, and increase total and hyperphosphorylated tau in WT mice. These results indicate that diet induced obesity of pR5 transgenic mice expressing P301L mutant human tau generates T2DM, and aggravates tau phosphorylation, and is therefore a model useful for investigations that seek to understand the relationships between AD, T2DM and obesity, and the underlying biochemical changes and mechanisms associated with metabolic disorders and AD tauopathy. Refereed/Peer-reviewed

Investigation of high-performance lasers monolithically grown on silicon (Si) could promote the development of silicon photonics in regimes other than the 1.3 -1.5 µm band. 980 nm laser, a widely used pumping source for erbium-doped fiber amplifier (EDFA) in the optical fiber communication system, can be used as a demonstration for shorter wavelength lasers. Here, we report continuous wave (CW) lasing of 980 nm electrically pumped quantum well (QW) lasers directly grown on Si by metalorganic chemical vapor deposition (MOCVD). Utilizing the strain compensated InGaAs/GaAs/GaAsP QW structure as the active medium, the lowest threshold current obtained from the lasers on Si was 40 mA, and the highest total output power was near 100 mW. A statistical comparison of lasers grown on native GaAs and Si substrates was conducted and it reveals a somewhat higher threshold for devices on Si. Internal parameters, including modal gain and optical loss are extracted from experimental results and the variation on different substrates could provide a direction to further laser optimization through further improvement of the GaAs/Si templates and QW design. These results demonstrate a promising step towards optoelectronic integration of QW lasers on Si.

Alzheimer’s disease (AD) is the most common cause of dementia among elderly people. Majority of AD cases are sporadic (SAD) with unknown cause. Transgenic animal models closely reflect the familial (genetic) aspect of the disease but not the sporadic type. However, most new drug candidates which are tested positive in transgenic animal models failed in clinical studies so far. Herein, we aim to develop an AD animal model that combines most of the neuropathological features seen in sporadic AD in humans with amyloid plaques observed in transgenic mice. Four-month-old wild-type and APP/PS1 AD mice were given a single intracerebroventricular (ICV) injection of 3 mg/kg streptozotocin (STZ), a diabetogenic agent. Three weeks later, their cognitive behavior was assessed, and their brain tissues were collected for biochemical and histological analysis. STZ produced cognitive deficits in both non-transgenic mice and AD mice. Biochemical analysis showed a severe decline in synaptic proteins, increase in tau phosphorylation, oxidative stress, disturbed brain insulin signaling with extensive neuroinflammation, and cell death. Significant increase was also observed in the level of the soluble beta amyloid precursor protein (APP) fragments and robust accumulation of amyloid plaques in AD mice compared to the control. These results suggest that STZ ICV treatment causes disturbance in multiple metabolic and cell signaling pathways in the brain that facilitated amyloid plaque accumulation and tau phosphorylation. Therefore, this animal model can be used to evaluate new AD therapeutic agents for clinical translation Refereed/Peer-reviewed

BACKGROUND: Blending technology is usually used to improve quality of dual-energy computed (DECT) images. OBJECTIVES: To evaluate the blended DECT image qualities by employing the Blending-Property-Map (BP-Map) and elucidating the optimal parameters with the highest signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). METHODS: Sixty pairs of 80 kV and 140 kV CT images are blended non-linearly by four methods. Protocol A uses the fixed values of blending width (BW) and blending center (BC); Protocol B uses the values of BW = (CThepatic portal vein – CThepatic parenchymal) / 2 and BC = (CThepatic portal vein + CThepatic parenchymal) / 2; Protocol C uses a BW ranging from 10 to 100 HU at an interval of 10 HU and BC = (CThepatic portal vein + CThepatic parenchymal) / 2; Protocol D uses the BP-Map that covers all possible values of BW and BC. RESULTS: When using CT value of adipose tissue as noise, the calculated SNR and CNR of optimal blending width and blending center were 123.22±41.73 and 9.00±3.52, respectively, by the BP-Map in the protocol D. By employing the CT value of back muscle as noise, the SNR and CNR of the best-blended images were 75.90±14.52 and 6.39±2.37, respectively. The subjective score of protocol D was 4.88±0.12. CONCLUSIONS: Compared to traditional blending methods, the BP-Map technique can determine the optimal blending parameter and provide the best-blended images with the highest SNR and CNR.

BACKGROUND: Previous studies have shown that using some post-processing methods, such as nonlinear-blending and linear blending techniques, has potential to improve dual-energy computed (DECT) image quality. OBJECTIVE: To improve DECT image quality of hepatic portal venography (CTPV) using a new non-linear blending method with computer-determined parameters, and to compare the results to additional linear and non-linear blending techniques. METHODS: DECT images of 60 patients who were clinically diagnosed with liver cirrhosis were selected and studied. Dual-energy scanning (80 kVp and Sn140 kVp) of CTPV was utilized in the portal venous phase through a dual-source CT scanner. For image processing, four protocols were utilized including linear blending with a weighing factor of 0.3 (protocol A) and 1.0 (protocol B), non-linear blending with fixed blending width of 200 HU and set blending center of 150HU (protocol C), and computer-based blending (protocol D). Several image quality indicators, including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and contrast of hepatic portal vein and hepatic parenchyma, were evaluated using the paired-sample t-test. A 5-grade scale scoring system was also utilized for subjective analysis. RESULTS: SNR of protocols A-D were 9.1±2.1, 12.1±3.0, 11.6±2.8 and 14.4±3.2, respectively. CNR of protocols A-D were 4.6±1.3, 8.0±2.3, 7.0±2.0 and 9.8±2.4, respectively. The contrast of protocols A-D were 37.7±11.6, 91.9±21.0, 66.2±19.0 and 107.7±21.3, respectively. The differences between protocol D and other three protocols were significant (P

Background The single-nucleotide polymorphism SLC39A6 rs1050631 is strongly implicated in esophageal squamous cell carcinoma, leading us to question whether it may also play a role in gastric adenocarcima (GA). Methods We genotyped the SLC39A6 rs1050631 in 512 patients who underwent GA resection. All study subjects lived in an area of China with high GA incidence. Genotypes were examined for possible correlation with survival and recurrence. The potential involvement of SLC39A6 in gastric cancer was explored in clinical samples and cell culture studies. Results Multivariable analysis showed that patients with the CT + TT genotype at SLC39A6 rs1050631 were at greater risk of recurrence (hazard ratio, HR 1.387, p = 0.004) and death (HR 1.429, p = 0.002) than patients with CC genotype. Median recurrence-free and overall survival were significantly shorter in patients with the CT + TT genotype (20, 27 months) than in patients with the CC genotype (36, 43 months, p = 0.001, p Conclusion SLC39A6 rs1050631 correlates with post-resection prognosis of GA patients and SLC39A6 may participate in GA onset or progression.

This paper reports the gain-switched InP-based $\boldsymbol{1.55 \mu\mathrm{m}}$ Qdash lasers on silicon. We investigated the laser performance and related physical parameters by carrying out gain-switching test for lasers on Si and InP. The future direction of improving laser performance was pointed by analyzing the parameters.

We investigated the effects of thermal cycle annealing (TCA) at high temperatures on the defect density and morphology of GaAs epilayers grown on (001) Si substrates. Several types of TCA combined with dislocation filter layers (DFLs) were introduced to reduce the defect densities in the GaAs grown on Si substrates. Plan-view transmission electron microscopy shows that the defect density of a 2.7 μm-thick GaAs/Si template with optimized TCA and DFLs is 1.4 × 107 cm−2, lower than a 1.1 μm-thick GaAs/Si template by a factor of 40. The surface roughness of the optimized GaAs/Si template is 1.3 nm after insertion of the DFLs. Additionally, optically pumped InP quantum dot micro-disk lasers (MDLs) were fabricated on these GaAs/Si templates to evaluate the template quality. Room-temperature continuous-wave lasing of 1.5 μm-diameter MDLs was observed, with ultralow lasing thresholds ranging from 0.5 to 2 μW.

Excellent performance of InAs quantum dot (QD) lasers grown on Si in the datacom and telecom bands has been reported in recent years. InP QD lasers on Si with emission wavelength at 650 nm–750 nm are seldom explored. In this paper, we report the growth and room temperature lasing of electrically pumped InP/GaAsP QD lasers directly grown on (001) Si emitting at 750 nm. The lowest threshold current density obtained is ∼650 A/cm2, measured on a 2 mm × 70 µm device. Moreover, the highest operating temperature of the InP QD laser grown on the GaAs/Si template is above 95°C. This 750 nm near red on-chip light source for the monolithic integration of Si photonics is potentially applicable in display, bio-photonics, and spatial mapping.

Direct epitaxy of InP quantum dot (QD) lasers on silicon (Si) provides an on-chip red laser source for integrated Si photonics with different applications. Here, we demonstrate the first, to the best of our knowledge, InP QD lasers directly grown on (001) Si. Combining highly emissive InP QDs and a GaAs/Si template with low defect density, continuous-wave (CW) lasing of micro-disk lasers (MDLs) on Si is achieved at room temperature. The lowest threshold of MDLs on Si is ∼ 500 n W , without considering the micro-disk surface absorption efficiency of the pump power. The MDLs grown on the native GaAs substrate with the same growth and fabrication process are compared using statistical data analysis. Similar material characterization results and device performances on these two substrates further confirm the performance of QD lasers on Si. This demonstration paves the way for future realization of integrated photonic circuits with red and near-infrared (NIR) lasers on Si.

The deployment of photonic integrated circuits (PICs) necessitates an integration platform that is scalable, high-throughput, cost-effective, and power-efficient. Here we present a monolithic InP on SOI platform to synergize the advantages of two mainstream photonic integration platforms: Si photonics and InP photonics. This monolithic InP/SOI platform is realized through the selective growth of both InP sub-micron wires and large dimension InP membranes on industry-standard (001)-oriented silicon-on-insulator (SOI) wafers. The epitaxial InP is in-plane, dislocation-free, site-controlled, intimately positioned with the Si device layer, and placed right on top of the buried oxide layer to form “InP-on-insulator”. These attributes allow for the realization of various photonic functionalities using the epitaxial InP, with efficient light interfacing between the III–V devices and the Si-based waveguides. We exemplify the potential of this InP/SOI platform for integrated photonics through the demonstration of lasers with different cavity designs including subwavelength wires, square cavities, and micro-disks. Our results here mark a critical step forward towards fully-integrated Si-based PICs., A monolithic InP/SOI platform with dislocation-free, site-controlled and in-plane InP sub-micron wire and large dimension InP membrane array selectively grown on (001) SOI platform.

Background Gastric cancer (GC) is one of the most common human cancers with the high rate of recurrence, metastasis and mortality. Aberrantly expressed microRNAs (miRNAs) are associated with invasion and metastasis in various human cancers. Recently, miR-188-5p has been indicated as an oncogene in GC since it promotes GC cell growth and metastasis. However, the underlying molecular mechanism remains to be fully defined. Methods Using Significance Analysis of Microarrays (SAM) screening, we identified that miR-188-5p is associated with overall survival and lymph node metastasis in patients with GC. The functional impact of miR-188-5p on GC metastasis was validated using in vitro and in vivo assays. The regulatory function of miR-188-5p on Wnt/β-catenin signaling activation through directly targeting PTEN was proven using quantitative real-time PCR, western blot analysis, a dual-luciferase assay, a Transwell assay, and immunofluorescence. Immunohistochemical analyses further confirmed the clinical significance of miR-188-5p in GC. Results MiR-188-5p diminishes tumor suppressor PTEN expression, and further increases phospho-Ser9 of GSK3β to activate Wnt/β-catenin signaling in GC. Consequently, miR-188-5p enhanced the migration and invasion of GC cells in vitro and tumor metastasis in vivo, whereas inhibition of miR-188-5p had the opposite effects. Moreover, miR-188-5p was negatively correlated with PTEN expression but positively correlated with nuclear β-catenin staining in GC samples. Conclusions Our findings revealed a model of the miR-188-5p-PTEN-β-catenin axis in GC, which mediates the constitutive activation of Wnt/β-catenin signaling and promotes tumor metastasis, inferring that miR-188-5p is a potential therapeutic target to treat GC. Electronic supplementary material The online version of this article (10.1186/s12885-019-5731-0) contains supplementary material, which is available to authorized users.

Coronavirus disease 2019 (COVID-19) emerged in Wuhan and rapidly spread throughout the world in December 2019. The present study aimed to describe the clinical characteristics and laboratory findings of 78 patients with COVID-19 in order to enhance the understanding of the disease. Medical records and data of 78 patients with COVID-19, including demographics, clinical features, laboratory findings and radiological characteristics, were collected and analyzed. Of the 78 hospitalized patients with COVID-19, the median age was 66.5 years and 48.7% of patients were male. Hypertension and diabetes were the most common chronic underlying diseases, and the most common symptoms were a cough and a fever. Furthermore, the most common findings on the chest CT were extensive ground-glass opacity and bilateral shadowing. Anemia and lymphocytopenia were the most common abnormalities identified during routine blood tests. COVID-19 caused early liver renal damage, with 52.9% of patients displaying elevated D-dimer levels, 98.7% of patients displaying elevated IL-6 levels and 80.8% of patients displaying a reduced level of low-density lipoprotein cholesterol (LDL-C). In the present single-center case study of 78 patients with COVID-19 in Wuhan, China, the patients displayed abnormal routine blood tests, liver function, renal function and levels of D-dimer, LDL-C and IL-6. Therefore, the development of drugs and vaccines that can be used to prevent and treat infections of COVID-19 is urgently required.

The thoracic cage plays an important role in maintaining the stability of the thoracolumbar spine. In this study, the influence of a rib cage on static and dynamic responses in normal and scoliotic spines was investigated. Four spinal finite element (FE) models (T1–S), representing a normal spine with rib cage (N1), normal spine without rib cage (N2), a scoliotic spine with rib cage (S1) and a scoliotic spine without rib cage (S2), were established based on computed tomography (CT) images, and static, modal, and steady-state analyses were conducted. In S2, the Von Mises stress (VMS) was clearly decreased compared to S1 for four bending loadings. N2 and N1 showed a similar VMS to each other, and there was a significant increase in axial compression in N2 and S2 compared to N1 and S1, respectively. The U magnitude values of N2 and S2 were higher than in N1 and S1 for five loadings, respectively. The resonant frequencies of N2 and S2 were lower than those in N1 and S1, respectively. In steady-state analysis, maximum amplitudes of vibration for N2 and S2 were significantly larger than N1 and S1, respectively. This study has revealed that the rib cage improves spinal stability in vibrating environments and contributes to stability in scoliotic spines under static and dynamic loadings.

Background. Scoliosis is a three-dimensional (3D) deformity of the spine, which affects the patient’s appearance and may lead to abnormal heart and lung function. The rib cage is a structure composed of ribs, sternum, and costal cartilage, which plays a vital role in stabilising the thoracolumbar spine. This study investigates the influence of the rib cage on the static characteristics of the scoliotic spine. Methods. Two types of 3D finite element (FE) models with or without rib cage (from T1 to S) were established and analysed based on computed tomography (CT) images, to determine the effects of the rib cage on the static characteristics of the scoliotic spine. The FE software, ABAQUS, was used to analyse the static behaviours of scoliotic spine models under a range of loading conditions, including left side bending, right side bending, front tilt, rear supine, and vertical compression. The changes in the von Mises stress (VMS) within the intervertebral discs of spine models with or without rib cage were studied and compared. Results. After including the rib cage, the maximum VMS at the stress concentrations of the normal and scoliotic spine effectively reduced. The VMS in normal intervertebral discs was gentler than that of scoliotic ones. However, the scoliotic spine was more likely to produce large stress concentration in the intervertebral discs of scoliotic segments. Conclusions. Under the common postures, intervertebral discs of scoliotic segments are more susceptible to generate stress concentrations compared with the normal spine. The rib cage could effectively keep the intervertebral discs of scoliotic segments from further injuries. These results are of great significance for the prevention and treatment of the scoliotic spine.

We present preliminary results of InAs/InAlGaAs quantum dash (QDash) micro-disk lasers directly grown on (001) silicon. Continuous-wave (CW) single-mode lasing at 1.6 μm under optical pumping is demonstrated with an average threshold of 0.96 mW.

We report the first demonstration of electrically-pumped continuous wave (CW) lasing of 1.5 µm quantum dash lasers directly grown on (001) silicon. Preliminary results include lowest threshold current density of 1.3 kA/cm2, and high temperature operation up to 59 oC in CW mode operation.

We present the growth of electrically pumped continuous-wave (CW) quantum dash (QDash) lasers on planar (001) Si emitting at 1.5 μm, with different active region structures. After growth optimization, the lowest threshold current, 2 kA/cm2 was obtained on a device grown on planar silicon.

Alzheimer's disease (AD) is the most common cause of dementia among elderly people. Majority of AD cases are sporadic (SAD) with unknown cause. Transgenic animal models closely reflect the familial (genetic) aspect of the disease but not the sporadic type. However, most new drug candidates which are tested positive in transgenic animal models failed in clinical studies so far. Herein, we aim to develop an AD animal model that combines most of the neuropathological features seen in sporadic AD in humans with amyloid plaques observed in transgenic mice. Four-month-old wild-type and APP/PS1 AD mice were given a single intracerebroventricular (ICV) injection of 3 mg/kg streptozotocin (STZ), a diabetogenic agent. Three weeks later, their cognitive behavior was assessed, and their brain tissues were collected for biochemical and histological analysis. STZ produced cognitive deficits in both non-transgenic mice and AD mice. Biochemical analysis showed a severe decline in synaptic proteins, increase in tau phosphorylation, oxidative stress, disturbed brain insulin signaling with extensive neuroinflammation, and cell death. Significant increase was also observed in the level of the soluble beta amyloid precursor protein (APP) fragments and robust accumulation of amyloid plaques in AD mice compared to the control. These results suggest that STZ ICV treatment causes disturbance in multiple metabolic and cell signaling pathways in the brain that facilitated amyloid plaque accumulation and tau phosphorylation. Therefore, this animal model can be used to evaluate new AD therapeutic agents for clinical translation.

Realization of fully integrated silicon photonics has been handicapped by the lack of a reliable and efficient III-V light source on Si. Specifically, electrically pumped continuous wave (CW) lasing and operation sustainable at high temperatures are critical for practical applications. Here, we present the first electrically pumped room temperature (RT) CW lasing results of 1.55 μm quantum dash (QDash) lasers directly grown on patterned on-axis (001) Si using metal organic chemical vapor deposition (MOCVD). Adopting a dash-in-well structure as the active medium, the growth of QDash was optimized on an InP on Si template. Incorporating the advantages of the optimized material growth and device fabrication, good laser performance including a low threshold current of 50 mA, a threshold current density of 1.3 kA/cm2 and operation at elevated temperature up to 59 °C in CW mode was achieved. Comparison of lasers grown on Si and native InP substrates in the same growth run was made. Based on the laser characteristics measured at room temperature and elevated temperatures, the QDash quality on the two substrates is comparable. These results suggest that MOCVD is a viable technique for lasers on Si growth and represent an advance towards silicon-based photonic-electronic integration and manufacturing.

The precursor of brain derived neurotrophic factor (proBDNF) and its receptor p75

Major depression is a leading cause of morbidity and disease burden in modern society. Current drug treatment is only effective in a fraction of patients as underlying mechanisms of depression are not fully understood. ProBDNF, a precursor of brain-derived neurotrophic factor (BDNF), and its receptor p75NTR are highly upregulated in patients with major depression and in animal models of depression induced by chronic stress. Here, we hypothesise that proBDNF may be a pathogenic factor triggering depression. C57BL/6 mice were injected in the bilateral gluteus maximus muscle with AAV-proBDNF or AAV-EGFP. Four weeks after the injection, AAV-proBDNF injected animals developed depression-like behaviours, which were evident for 4–8 weeks and then returned to the control level after 12 weeks. In the second experiment, mice were divided into three groups; one group was treated with sheep anti-proBDNF antibody after AAV-proBDNF injection whereas the other two groups received PBS injection after the AAV-proBDNF or AAV-EGFP delivery. The group that was injected with AAV-proBDNF showed a time-dependent increase in immobility time in the tail suspension test and forced swim test, reduced sucrose consumption and decreased grooming time after sucrose spraying. Treatment with sheep anti-proBDNF antibody alleviated the depressive-like symptoms. Peripheral AAV-proBDNF delivery also resulted in a reduction of density and length of dendritic spines in the dentate gyrus and amygdala. Thus, we conclude that peripheral proBDNF is a primary pathogenic factor triggering depression-like behavioural changes in mice likely by reducing dendritic spine plasticity. Refereed/Peer-reviewed

A micro-fabricated planar bi-stable mechanical latch is demonstrated and presently reported. The compact size of the bi-stable mechanism is achieved by enclosing an anchored latch groove in the center of other movable structures. Driven using a single actuator, the device can be switched mechanically between two stable states by applying respective setting and resetting voltage of 10.3 V and 9.5 V. Exhibiting good durability and promising potential for applications demanding micro-switches, the device was demonstrated as an electrical switch to control a light-emitting diode.

Brain derived neurotrophic factor (BDNF) is a member of the neurotrophin family, best characterized for its survival and differentiative effects in the central nervous system. Pro-BDNF, known as the precursor of BDNF, is believed to have opposite functions to mature BDNF (mBDNF). The opposing effects of Pro-BDNF and mBDNF have led researchers to propose a ‘yin’ (Pro-BDNF) and ‘yang’ (mBDNF) model of which, the specific mechanism of its opposing functions is unclear and requires further investigation. In order to elucidate pro-BDNF's explicit role, we established a pro-BDNF knockout (KO) mouse model. This BDNF pro-domain KO mouse model showed significant weight loss, impaired righting reflex, abnormal motor behaviours and short lifespan (less than 22 days), mimicking a Huntington's disease (HD)-like phenotype. ELISA results showed BDNF pro-domain KO not only blocked pro-BDNF, but also significantly affected the level of mBDNF. Abnormal morphologic changes were found in the dentate gyrus (DG) of the hippocampus in pro-BDNF KO mice, and western blot confirmed significant cell apoptosis in pro-BDNF KO mice brains. Furthermore, the expression of glutamic acid decarboxylase 65/67 (GAD65/67) was significantly reduced in pro-BDNF KO mice, indicating impaired inhibitory neurotransmission. Heterozygous (Het) mice showed impaired learning and memory capability and depressive-like behaviours, compared with wild type (WT) mice. Overall, these results support that pro-domain of BDNF is an indispensable part of the BDNF gene; without the proper formation of pro-BDNF, mBDNF cannot be produced successfully and function correctly on its own. Our study also supports the BDNF hypothesis in the pathogenesis of HD Refereed/Peer-reviewed

The purpose of this study is to reveal the protective effect of rib cage on scoliotic spine by comparing the different effect of rib cage on the stability of normal spine and Lenke1 scoliotic spine. Firstly, according to X-ray computed tomography (CT) image data, four spinal finite element models (SFEMs), including normal spine without rib cage (N1), normal spine with normal rib cage (N2), scoliotic spine without rib cage (S1) and scoliotic spine with deformed rib cage (S2), from the first thoracic vertebrae to the sacral vertebrae (T1～S) were established. Secondly, the natural vibration characteristics of the four SFEMs were obtained by modal analysis. Finally, the maximum vibration amplitudes of the four SFEMs under external excitation were obtained by steady-state analysis. As shown in results, compared with N1, the maximum deformation of N2 segment T4～T6 in the X-axis (coronal axis), Y-axis (sagittal axis) and Z-axis (vertical axis) directions decreases by 38.44%, 53.80% and 33.72%, respectively. Compared with S1, the maximum deformation of S2 segment T4～T6 in the X-axis direction, Y-axis direction and Z-axis directions decreases by 44.26%, increases by 32.80% and decreases by 49.23%, respectively. As it can be seen, for normal spine, the rib cage can improve the stability of the whole spine in three directions; for the Lenke1 scoliotic spine, the rib cage can reduce the vibration of the scoliotic spine in the X-axis and Z-axis directions and improves the stability of the whole spine in the two directions, while in the Y-axis direction, for the serious severe anteversion of scoliotic spine, the deformed rib cage exacerbates the vibration of the scoliotic spine in this direction and destroys the stability of the scoliotic spine in the Y-axis direction. This study reveals the biomechanical characteristics of rib caged influence on the stability of the scoliotic spine and it has guiding significance for the study of daily protection methods and protective tools for scoliotic patients.

Quantum-dot (QD) and quantum-dash (QDash) have been shown to be promising gain materials for lasers directly grown on Si due to their better tolerance to crystal defects and thermal stability. Here we report optically pumped InP-based InAs QDash microdisk lasers (MDLs) directly grown on on-axis (001) Si. To the best of our knowledge, this is the first demonstration of room-temperature continuous-wave lasing of a QDash MDL on Si in the C band and L band. To the best of our knowledge, the lowest threshold of around 400 µW and highest operation temperature of 323 K have been achieved. An analysis of experimental results shows that the dominant lasing wavelength of MDLs varies with the thickness and diameter of the MDLs. Our demonstration shows potential application of MDLs for multi-channel operation in densely integrated Si-photonics.