Butylparaben induced zebrafish (Danio rerio) kidney injury by down-regulating the PI3K-AKT pathway.

Butylparaben, a common endocrine disruptor in the environment, is known to be toxic to the reproductive system, heart, and intestines, but its nephrotoxicity has rarely been reported. In order to study the nephrotoxicity and mechanism of butylparaben, we examined the acute and chronic effects on human embryonic kidney cells (HEK293T) and zebrafish. Additionally, we assessed the potential remedial effects of salidroside against butylparaben-induced nephrotoxicity. Our in vitro findings demonstrated oxidative stress and cytotoxicity to HEK293T cells caused by butylparaben. In the zebrafish model, the concentration of butylparaben exposure ranged from 0.5 to 15 µM. An assortment of experimental techniques was employed, including the assessment of kidney tissue morphology using Hematoxylin-Eosin staining, kidney function analysis via fluorescent dextran injection, and gene expression studies related to kidney injury, development, and function. Additionally, butylparaben caused lipid peroxidation in the kidney, thereby damaging glomeruli and renal tubules, which resulted from the downregulation of the PI3K-AKT signaling pathway. Furthermore, salidroside ameliorated butylparaben-induced nephrotoxicity through the PI3K-AKT signaling pathway. This study reveals the seldom-reported kidney toxicity of butylparaben and the protective effect of salidroside against toxicological reactions related to nephrotoxicity. It offers valuable insights into the risks to kidney health posed by environmental toxins.

The Potential Mediating Effect of Symptom Burden on Demoralization Through Locus of Control and Coping Strategies in Chinese Patients With Cancer.

BACKGROUND: Demoralization is a psychological syndrome that is highly prevalent in patients with cancer and detrimental to individuals' physical and mental health. To explore effective intervention, we first determined the relationships between locus of control, coping strategies, symptom burden, and demoralization. OBJECTIVE: The aim of this study was to determine the relationship between symptom burden, locus of control, coping strategies, and demoralization in patients with cancer. METHODS: In this descriptive-correlational study, 273 valid patients were selected with convenience sampling method from a hospital in China. Data were collected using the Chinese version of the M.D. Anderson Symptom Inventory, the Chinese version of the Multidimensional Health Locus of Control Scale, the Chinese version of the Medical Coping Modes Questionnaire, and the Mandarin version of the Demoralization Scale. Data were analyzed using descriptive and inferential statistics using SPSS and AMOS. RESULTS: A total of 115 patients (42.12%) experienced clinical demoralization (Mandarin version of the Demoralization Scale > 30). Symptom burden (ß = 0.295, P < .001), confrontation (ß = -0.117, P = .028), and resignation (ß = 0.456, P < .001) had direct effects on demoralization. Symptom burden also had an indirect effect on demoralization through the mediating role of resignation (ß = 0.026, P = .002). Meanwhile, locus of control can affect demoralization entirely through the indirect mediating role of coping strategies (chance locus of control via resignation [ß = 0.138, P < .01], powerful locus of control via confrontation [ß = -0.017, P < .05]). CONCLUSIONS: Symptom burden affects demoralization not only directly but also indirectly. Coping strategies play an important mediating role between symptom burden, locus of control, and demoralization in patients with cancer. IMPLICATIONS FOR PRACTICE: It is urgent to screen demoralization and identify patients with high symptom burden, maladaptive locus of control, or coping strategies. For the patients targeted, a more comprehensive and systematic approach to symptom management and more appropriate guidance related to adaptive coping strategies are needed.

Ammonia removal and simultaneous immobilization of manganese and magnesium from electrolytic manganese residue by a low-temperature CaO roasting process.

A large amount of open-dumped electrolytic manganese residue (EMR) has posed a severe threat to the ecosystem and public health due to the leaching of ammonia (NH4+) and manganese (Mn). In this study, CaO addition coupled with low-temperature roasting was applied for the treatment of EMR. The effects of roasting temperature, roasting time, CaO-EMR mass ratio and solid-liquid ratio were investigated. The most cost-effective and practically viable condition was explored through response surface methodology. At a CaO: EMR ratio of 1:16.7, after roasting at 187 °C for 60 min, the leaching concentrations of NH4+ and Mn dropped to 10.18 mg/L and 1.05 mg/L, respectively, below their discharge standards. In addition, the magnesium hazard (MH) of EMR, which was often neglected, was studied. After treatment, the MH of the EMR leachate was reduced from 60 to 37. Mechanism analysis reveals that roasting can promote NH4+ to escape as NH3 and convert dihydrate gypsum to hemihydrate gypsum. Mn2+ and Mg2+ were mainly solidified as MnO2 and Mg(OH)2, respectively. This study proposes an efficient and low-cost approach for the treatment of EMR and provides valuable information for its practical application.

Multifunctional MXene-doped photothermal microneedles for drug-resistant bacteria-infected wound healing.

Skin injuries and drug-resistant bacterial infections pose serious challenges to human health. It is essential to establish a novel multifunctional platform with good anti-infection and wound-healing abilities. In this study, a new MXene-doped composite microneedle (MN) patch with excellent mechanical strength and photothermal antibacterial and ROS removal properties has been developed for infected wound healing. When the MN tips carrying the MXene nanosheets are inserted into the cuticle of the skin, they will quickly dissolve and subsequently release the nanomaterials into the subcutaneous infection area. Under 808 nm NIR irradiation, the MXene, as a "nano-thermal knife", sterilizes and inhibits bacterial growth through synergistic effects of sharp edges and photothermal antibacterial activity. Furthermore, ROS caused by injury and infection can be cleared by MXene-doped MNs to avoid excessive inflammatory responses. Based on the synergistic antibacterial and antioxidant strategy, the MXene-doped MNs have demonstrated excellent wound-healing properties in an MRSA-infected wound model, such as promoting re-epithelialization, collagen deposition, and angiogenesis and inhibiting the expression of pro-inflammatory factors. Therefore, the multifunctional MXene-doped MN patches provide an excellent alternative for clinical drug-resistant bacteria-infected wound management.

Research on the development and innovation of online education based on digital knowledge sharing community.

BACKGROUND: Digital knowledge sharing (DKS) communities have emerged as a promising approach to support learning and innovation in online higher education. These communities facilitate the exchange of knowledge, resources, and ideas among educators, students, and experts, creating opportunities for collaboration, innovation, and lifelong learning. However, the impact and role of DKS communities in online education are not well understood, and further research is needed to explore their potential benefits and challenges. PURPOSE: This multi-objective qualitative study aims to investigate the impact and role of DKS communities in online higher education, identifying the factors that promote student success and the implications for the development of online education. The study collected data from 20 informants who have experienced teaching online during and after the pandemic. Data were collected through in-depth interviews and analyzed using thematic analysis. The informants were selected through theoretical sampling. METHODOLOGY: To explore the impact and role of DKS communities in online higher education, this study employed a multi-objective qualitative research method. Data were collected through in-depth interviews conducted with 20 informants who possessed experience in teaching online during and after the pandemic. The informants were selected through theoretical sampling to ensure diverse perspectives and insights. The collected data were subsequently analyzed using thematic analysis, allowing for the identification of key themes and patterns. FINDINGS: The findings of this study provide valuable insights into the impact and role of DKS communities in online higher education. These insights encompass various aspects, including the benefits and challenges of DKS in online education, the factors that contribute to student success, and the implications for the ongoing development and innovation of online education. CONCLUSIONS: In conclusion, this multi-objective qualitative study sheds light on the significance of DKS communities in online higher education. It underscores their potential to enhance collaboration, innovation, and lifelong learning. The findings also emphasize the importance of addressing challenges and fostering an inclusive and supportive online learning environment. These insights inform best practices and contribute to the continuous development and innovation of online education, particularly in the post-pandemic educational landscape.

Optically transparent and flexible-assembled metasurface rasorber for infrared-microwave camouflage based on a hybrid anapole state.

Hybrid anapole state, originating from the destructive interference of more than one basic electromagnetic multipole moments with their toroidal counterparts, enables the simultaneous suppression of multiple leading scattering channels, thereby demonstrates promising applications in perfect absorption and electromagnetic camouflage. However, the formation of hybrid anapoles is challenging because a careful overlap of electromagnetic multipoles with their toroidal counterparts is required. In this study, we propose and experimentally demonstrate a transparent and flexible assembled metasurface rasorber supporting hybrid anapole states for infrared and microwave camouflage, which not only supports low IR emissivity in the range of 8-14 µm but also exhibits an absorption-transmission-absorption response in the microwave band. In addition, the conformal and tunable performances of the fabricated metasurface rasorber are experimentally demonstrated. Our study provides a new strategy for designing multispectral camouflage metasurfaces.

Investigating the Microscopic Mechanism of Ultrasonic-Vibration-Assisted-Pressing of WC-Co Powder by Simulation.

The ultrasonic-vibration-assisted pressing process can improve the fluidity and the uneven distribution of density and particle size of WC-Co powder. However, the microscopic mechanism of ultrasonic vibration on the powder remains unclear. In this paper, WC particles with diameter 5 µm and Co particles with diameter 1.2 µm were simulated by three-dimensional spherical models with the aid of the Python secondary development. At the same time, the forming process of the powder at the mesoscale is simulated by virtue of the finite element analysis software ABAQUS. In the simulation process, the vibration amplitude was set to 1, 2, and 3 µm. Their influence on the fluidity, the filling density, and the stress distribution of WC-Co powder when the ultrasonic vibration was applied to the conventional pressing process was investigated. The simulation results show that the ultrasonic vibration amplitude has a great influence on the density of the compact. With an increase in the ultrasonic amplitude, the compact density also increases gradually, and the residual stress in the billet decreases after the compaction. From the experimental results, the size distribution of the billet is more uniform, the elastic after-effect is reduced, the dimensional instability is improved, and the density curves obtained by experimentation and simulation are within a reasonable error range.

Safety and immunogenicity of a skin- and neuro-attenuated live vaccine for varicella: a randomized, double-blind, controlled, dose-escalation and age de-escalation phase 1 clinical trial.

Background: Despite the success in decreasing varicella-related disease burden, live-attenuated Oka vaccine strain of varicella-zoster virus (vOka) remains neuro-virulence and may establish latency and reactivate, raising safety concerns. Here we aimed to evaluate the safety and immunogenicity of a skin- and neuro-attenuated varicella vaccine candidate (v7D). Methods: This is a randomized, double-blind, placebo-controlled, dose-escalation and age de-escalation phase 1 clinical trial conducted in Liuzhou, China (ChiCTR1900022284). Eligible healthy participants aged 1-49 years, with no history of varicella vaccination and had no history of varicella or herpes zoster were sequentially enrolled and allocated to subcutaneously receive one of the three doses (3.3, 3.9, and 4.2 lg PFU) of v7D, vOka or placebo in a dose-escalation and age de-escalation manner. The primary outcome was safety, assessed by adverse events/reactions within 42 days after vaccination and serious adverse events (SAEs) throughout six months after vaccination. The secondary outcome was immunogenicity, assessed by the VZV IgG antibodies measured with fluorescent antibody to membrane antigen (FAMA) assay. Findings: Between April 2019 and March 2020, totally 224 participants were enrolled. Within 42 days post-vaccination, the incidences of adverse reactions were 37.5%-38.7% in the three doses of v7D groups which were similar to that of the vOka (37.5%) and placebo (34.4%) groups. No SAE has been judged as causally related to vaccination. At 42 days post-vaccination, 100% of children aged 1-12 years in the per-protocol set of immunogenicity cohort of the v7D groups became seropositive. Meanwhile, in the intent-to-treat set of immunogenicity cohort of subjects aged 1-49 years, the geometric mean increases of the three groups of v7D vaccine were 3.8, 5.8 and 3.2, respectively, which were similar to that of the vOka vaccine group (4.4) and significantly higher than that of the placebo group (1.3). Interpretation: The candidate v7D vaccine has been preliminarily shown to be well-tolerated and immunogenic in humans. The data warrant further evaluation of the safety advantage and efficacy of v7D as a varicella vaccine. Funding: The National Natural Science Foundation of China, CAMS Innovation Fund for Medical Sciences, and Beijing Wantai CO., LTD.

Effect of bionic hexagonal texture on squeezing films inside soft contacts with high adhesion and high friction.

To understand the mechanisms of high friction and high adhesion in bioinspired textured surfaces under wet conditions, the evolution behavior of squeezing films across lubricated interfaces is experimentally investigated using optical interferometry. The results show that the splitting of the continuous large-scaled liquid film into numerous isolated micro zones is an important function of the hexagonal texture. Both the orientation and the size of the hexagonal texture have noticeable effects on the drainage rate: either downscaling the hexagonal texture or orienting the texture with two sides of each micro-hexagon parallel to the inclining direction could accelerate the draining process. While the draining process is completed, residual micro-droplets turn out to be entrapped within the contact regions of single hexagonal micro-pillars. The entrapped micro-droplets gradually shrink as the hexagonal texture downsizes. Moreover, a novel geometrical shape for the micro-pillared texture is proposed to improve the drainage efficiency.

Safety and immunogenicity of a bivalent HPV16/18 vaccine in Chinese females.

As global supply is still inadequate to address the worldwide requirements for HPV vaccines, we assessed the safety and immunogenicity of a new bivalent HPV16/18 vaccine. In this randomized, double-blind, placebo-controlled, phase 2 trial, healthy 9-45-year-old Chinese females in three age cohorts (600 aged 9-17 years; 240 aged 18-26 years; 360 aged 27-45 years) were randomized 1:1 to receive three doses (0,2,6 months) of HPV16/18 vaccine or placebo. We measured neutralizing antibodies against HPV 16 and 18 at 7 months and monitored safety to 12 months in all age cohorts; 9-17-year-old girls were monitored for safety and immunogenicity to 48 months. In vaccinees, 99.8% seroconverted for HPV 16 and 18 types at 7 months; respective GMTs of 5827 (95% CI: 5249, 6468) and 4223 (3785, 4713) were significantly (p < .001) higher than controls for all comparisons. GMTs in the 9-17-year-olds, which were significantly higher than in older women at 7 months, gradually declined to 48 months but remained higher than placebo with seropositivity rates maintained at 98.5% and 97.6% against HPV 16 and 18, respectively. Adverse events occurred at similar rates after vaccine and placebo (69.8% vs. 72.5%, p = .308), including solicited local reactions and systemic adverse events which were mainly mild-to-moderate. The bivalent HPV16/18 vaccine was well tolerated and induced high levels of neutralizing antibodies in all age groups which persisted at high levels to 48 months in the 9-17-year-old age group which would be the target for HPV vaccination campaigns.

Safety and immunogenicity of a pichia pastoris-expressed bivalent human papillomavirus (types 16 and 18) L1 virus-like particle vaccine in healthy Chinese women aged 9-45 years: A randomized, double-blind, placebo-controlled phase 1 clinical trial.

BACKGROUND: We evaluated the safety and immunogenicity of high and low doses of a novel pichia pastoris-expressed bivalent (types 16 and 18) human papillomavirus (HPV) virus-like particle vaccine. METHODS: In this randomized, double-blind, placebo-controlled phase 1 trial, we enrolled 160 healthy females aged 9-45 years in Guangxi, China who were randomized (1:1:2) to receive either low (0.5 mL) or high (1.0 mL) dosages of bivalent HPV vaccine, or placebo (aluminum adjuvant) in a 0, 2, 6 months schedule. Adverse events and other significant conditions that occurred within 30 days after each vaccination were recorded throughout the trial. Sera were collected at days 0, 60, 180 and 210 to measure anti-HPV 16/18 neutralizing antibodies. RESULTS: A total of 160 participants received at least one dose of the HPV vaccine and 152 completed the three dose vaccination series. Reporting rates of adverse events in placebo, low dose (0.5 mL) and high dose (1.0 mL) groups were 47.5 %, 55.0 % and 55.0 %, respectively. No serious adverse events occurred during this trial. 100 % of the participants who received three doses of the HPV vaccine produced neutralizing antibodies against HPV 16/18 vaccine. For HPV 16 and HPV 18, the geometric mean titers (GMTs) were similar between the low dose group (GMTHPV 16 = 10816 [95 % CI: 7824-14953]), GMTHPV 18 = 3966 [95 % CI: 2693-5841]) and high dose group (GMT HPV 16 = 14482 [95 % CI: 10848-19333], GMT HPV 18 = 3428 [95 % CI: 2533-4639]). CONCLUSION: The pichia pastoris-expressed bivalent HPV vaccine was safe and immunogenic in Chinese females aged 9-45 years. The low dosage (0.5 mL) was selected for further immunogenicity and efficacy study.

Factors associated with negative conversion of viral RNA in hospitalized children infected with SARS-CoV-2 Omicron variant in Shanghai, China: a retrospective analysis.

OBJECTIVES: This study aimed to identify the related risk factors and potential predictors of SARS-CoV-2 RNA negative conversion by describing the dynamics of viral shedding in infected children admitted to two hospitals from Shanghai during the Omicron variant outbreak. METHODS: This retrospective cohort included laboratory-confirmed cases of SARS-CoV-2 infection from Shanghai between March 28 and May 31, 2022. Clinical characteristics, personal vaccination, and household vaccination rates were collected through electronic health records and telephone interviews. RESULTS: A total of 603 paediatric patients confirmed to have COVID-19 were included in this study. Both univariate and multivariate analyses were performed to filter independent factors for the duration to viral RNA negative conversion. Data on the redetection of SARS-CoV-2 in the patients after they showed negative results on the RT‒PCR test (intermittent negative status) were also analysed. The median duration of virus shedding was 12 (interquartile range, IQR: 10-14) days. The severity of clinical outcome, personal vaccination-2doses, household vaccination rates, and abnormal defecation were factors indecently affecting negative conversion of SARS-CoV-2 RNA, suggesting that patients who had abnormal defecation or with more severe conditions would have delayed virological clearance, while patients who previously had 2 doses of vaccination or had higher household vaccination rates would have accelerated virological clearance. Loss of appetite (odds ratio (OR): 5.343; 95% CI: 3.307-8.632) and abnormal defecation (OR: 2.840; 95% CI: 1.736-4.645) were significantly associated with intermittent negative status. CONCLUSION: These findings could provide clues for the early identification of paediatric patients with prolonged viral shedding and could enrich the evidence for the development of prevention and control strategies, especially vaccination policies for children and adolescents.

Flexible and transparent metadevices for terahertz, microwave, and infrared multispectral stealth based on modularization design.

Multispectral stealth technology including terahertz (THz) band will play an increasingly important role in modern military and civil applications. Here, based on the concept of modularization design, two kinds of flexible and transparent metadevices were fabricated for multispectral stealth, covering the visible, infrared (IR), THz, and microwave bands. First, three basic functional blocks for IR, THz, and microwave stealth are designed and fabricated by using flexible and transparent films. And then, via modular assembling, that is, by adding or removing some stealth functional blocks or constituent layers, two multispectral stealth metadevices are readily achieved. Metadevice 1 exhibits THz-microwave dual-band broadband absorption, with average measured absorptivity of 85% in 0.3-1.2 THz and higher than 90% in 9.1-25.1 GHz, suitable for THz-microwave bi-stealth. Metadevice 2 is for IR and microwave bi-stealth, with measured absorptivity higher than 90% in 9.7-27.3 GHz and low emissivity around 0.31 in 8-14 µm. Both metadevices are optically transparent and able to maintain good stealth ability under curved and conformal conditions. Our work offers an alternative approach for designing and fabricating flexible transparent metadevices for multispectral stealth, especially for applications in nonplanar surfaces.

Diflovidazin damages the hematopoietic stem cells to zebrafish embryos via the TLR4/ NF-κB/ p53 pathway.

Exposure to environmental contaminants frequently induces the occurrence of blood diseases, but the underlying molecular mechanisms are scarcely known. The toxicity of Diflovidazin (DFD), a widely used mite-remover, to the blood system of non-target organisms requires urgent elucidation. To investigate the deleterious effects of DFD (2, 2.5, and 3 mg/L) on the development and survive of hematopoietic stem cells (HSCs), the zebrafish model was used in this study. DFD exposure reduced the number of HSCs and their subtypes, including macrophages, neutrophils, thymus T-cells, erythrocytes, and platelets. The significant changes in the abnormal apoptosis and differentiation of HSCs were the major reasons for the reduction in blood cells. Using small-molecule antagonists and p53 morpholino revealed that the NF-κB/p53 pathway was responsible for the apoptosis of HSCs upon DFD exposure. The restoration results attributed to the TLR4 inhibitor and molecular docking showed that the TLR4 protein, which was upstream of NF-κB signaling, played a vital role in DFD toxicology. This study elucidates the role and molecular mechanism of DFD in damaging zebrafish HSCs. It provides a theoretical basis for the occurrence of various blood diseases in zebrafish and other organisms.

MXene-Functionalized Ferroelectric Nanocomposite Membranes with Modulating Surface Potential Enhance Bone Regeneration.

Rapid and effective bone defect repair remains a challenging issue for clinical treatment. Applying biomaterials with endogenous surface potential has been widely studied to enhance bone regeneration, but how to regulate the electric potential and surface morphology of the implanted materials precisely to achieve an optimal bioelectric microenvironment is still a major challenge. The aim of this study is to develop electroactive biomaterials that better mimic the extracellular microenvironment for bone regeneration. Hence, MXene/polyvinylidene fluoride (MXene/PVDF) ferroelectric nanocomposite membranes were prepared by electrospinning. Physicochemical characterization demonstrated that Ti3C2Tx MXene nanosheets were wrapped in PVDF shell layer and the surface morphology and potential were modulated by altering the content of MXene, where uniform distribution of fibers and enhanced electric potential can be obtained and precisely assembled into a natural extracellular matrix (ECM) in bone tissue. Consequently, the MXene/PVDF membranes facilitated cell adhesion, stretching, and growth, showing good biocompatibility; meanwhile, their intrinsic electric potential promoted the recruitment of osteogenic cells and accelerated the differentiation of osteoblast. Furthermore, 1 wt % MXene/PVDF membrane with a suitable surface potential and better topographical structure for bone regeneration qualitatively and quantitatively promoted bone tissue formation in a rat calvarial bone defect after 4 and 8 weeks of healing. The fabricated MXene/PVDF ferroelectric nanocomposite membranes show a biomimetic microenvironment with a sustainable electric potential and optimal 3D topographical structure, providing an innovative and well-suited strategy for application in bone regeneration.

Analysis of epidemic characteristics and related factors of norovirus in diarrhea patients in Guangxi, 2015-2020 / 中国热带医学

@#Abstract: Objective　To analyze the epidemiological characteristics and related factors of norovirus in Guangxi from 2015 to 2020, and to provide scientific recommendations for norovirus prevention and control. Methods The foodborne diseases surveillance data were collected from 11 sentinel hospitals through the National Foodborne Disease Monitoring and Reporting System from 2015 to 2020. R software with version 4.0.3 was used for descriptive and statistical analysis, including epidemic curve, chi-square test, and trend chi-square and so on. Logistic regression was used to analyze norovirus-related factors, OR values and 95% confidence intervals were calculated respectively with the statistical test level of P<0.05. Results There were 1 008 norovirus cases detected, with a detection rate of 12.75% (1 008/7 903). Children with age less than 5 years (OR=1.43, 95%CI: 1.13-1.82) and patients at age 20-45 (OR=1.45, 95%CI: 1.13-1.87) were high risk population. The detection rate was higher in autumn (OR=1.29, 95%CI: 1.08-1.53) but lower in summer (OR=0.67, 95%CI: 0.55-0.80). In addition, the tourist area (Guilin City) presented a higher detection rate than other areas (OR=1.41, 95%CI: 1.10-1.80). Aquatic products (OR=1.40, 95%CI: 1.03-1.91), meat and dairy products (OR=1.31, 95%CI: 1.06-1.61) were high-risk foods for norovirus infection. The prevention and control policies of COVID-19 can reduce the possibility of norovirus by 61% (OR=0.39, 95%CI: 0.31-0.49) showed a declining trend (Trend χ2=85.33, P<0.001). In addition, prolonged visit time can lead to 19%-23% decrease in the detection rate of norovirus (OR24-48 hours=0.81, 95%CI: 0.70-0.95; OR>48 hours=0.77, 95%CI: 0.63-0.93). Conclusions　The epidemic of norovirus presented seasonal and regional distribution in Guangxi with a declining detection rate trend in diarrhea patients during recent 6 years. Young children were high-risk population in infection norovirus. The intake of seafood can increase the risk of norovirus infection. The prevention and control policies of COVID-19 can sharply decrease the possibility of infection norovirus. The monitoring of key foods such as seafood should be strengthened, and the early screening of suspected cases should be taken. The norovirus monitoring should be improved to ensure the health of the population.

Wide-waveguide high-power low-RIN single-mode distributed feedback laser diodes for optical communication.

We present an 8-µm-wide 800-µm-long high-power, single-mode and low RIN DFB laser using a dual-waveguide structure. The introduced passive lower waveguide has weakenes the lateral optical confinement for the ridge waveguide, and thus reduces losses caused by the p-doped layers and maintains single mode stability of the laser. The fabricated laser exhibited an output power higher than 170 mW and a relative intensity noise (RIN) below -157 dB/Hz along with a side-mode suppression-ratio (SMSR) over 55 dB. The temperature tuning from -10°C to 60°C allows an 8.6 nm wavelength tunability with a variation coefficient of 0.12 nm/K. The relaxation oscillation frequency is around 8 GHz, and the linewidth is about 250 kHz at 100 mW output power for the fabricated laser. The characteristics of the proposed high-power laser, including high slope efficiency, single mode stability and low noise, make it a suitable candidate for optical communication.

Influence of Pulse Energy and Defocus Amount on the Mechanism and Surface Characteristics of Femtosecond Laser Polishing of SiC Ceramics.

SiC ceramics have excellent comprehensive properties and are typical hard and brittle materials that are difficult to process and are widely used in many fields. Laser polishing technology has developed into a new surface processing technology, and femtosecond laser polishing has become an important method for the precision machining of hard and brittle materials. In this paper, SiC ceramics were ablated and polished by infrared femtosecond laser, the laser ablation threshold of SiC ceramics was calculated and the influence of pulse energy and defocus amount on the surface morphology, surface roughness, polishing depth and oxidation degree of femtosecond laser polishing of SiC ceramics were investigated. The results show that when the laser repetition frequency f = 175 kHz, wavelength λ = 1064 nm and ablation time t = 9 s, the laser ablation threshold of SiC ceramics is 0.355 J/cm2. With the increase in pulse energy, the surface roughness first decreased and then increased, and the polishing depth showed an overall upward trend. The change of defocus amount will lead to the change of the laser spot diameter. With the increase of the defocus amount, the laser spot irradiated on the workpiece surface becomes larger, and the laser energy density decreases, which results in the decrease of the laser ablation ability and polishing depth and the increase of the polished surface roughness. Periodic nano-ripple structures appeared on the laser-induced surface. Through Energy Dispersive Spectrometer (EDS) elemental analysis, it was found that there was an oxidation phenomenon in SiC ceramics polished by femtosecond laser in an air environment, and the change of pulse energy and defocus amount had insignificant effects on the degree of oxidation.

A Retrospective Study of Effectiveness of Thoracoscopic Lobectomy and Segmentectomy in Patients with Early-Stage Non-Small-Cell Lung Cancer.

Background: Surgical treatment is the first choice for non-small-cell lung cancer. To date, there are only few studies on the changes in laboratory indexes in two types of surgery, namely, thoracoscopic lobectomy and segmental pneumonectomy. Aim: To investigate the clinical impact of thoracoscopic lobectomy and segmentectomy in patients with early-stage non-small-cell lung cancer. Methods: We retrospectively reviewed the medical records of 94 patients with early-stage NSCLC in our hospital from October 2017 to October 2019. The patients were divided into two groups. The patients in control and observation groups received thoracoscopic lobectomy and thoracoscopic segmentectomy, respectively. The perioperative indicators, complications, lung function, T cell subsets, tumor markers, follow-up of tumor recurrence rate, and survival rate were compared between two groups. Results: The operation time of the observation group was longer, and the chest drainage volume was less at 24-48 h after the operation, and the chest tube indwelling time and postoperative hospital stay were shorter than those of the control group. No significant differences in complication probability were observed between two groups. The levels of FEV1, FVC, and MVV in the two groups were lower than those before the operation at 3 days after surgery, but the FEV1, FVC, and MVV levels in the observation group were higher than those in the control group. The CD3+, CD4+, and CD4+/CD8+ levels in the two groups were lower than those before the operation at 24 h and 72 h after the operation, but CD3+, CD4+, and CD4+/CD8+ levels in the observation group were higher than those of the control group. Conclusion: Thoracoscopic lobectomy and segmental resection have similar clinical effects in the treatment of early-stage NSCLC patients, but segmental resection can preserve healthy lung tissue as much as possible, with less trauma, protect lung function, and promote postoperative recovery.