Elimination of methicillin‑resistant Staphylococcus aureus biofilms on titanium implants via photothermally‑triggered nitric oxide and immunotherapy for enhanced osseointegration

Background:Treatment of methicillin-resistant Staphylococcus aureus(MRSA)biofilm infections in implant placement surgery is limited by the lack of antimicrobial activity of titanium(Ti)implants.There is a need to explore more effective approaches for the treatment of MRSA biofilm infections.Methods:Herein,an interfacial functionalization strategy is proposed by the integration of mesoporous polydopamine nanoparticles(PDA),nitric oxide(NO)release donor sodium nitroprusside(SNP)and osteogenic growth peptide(OGP)onto Ti implants,denoted as Ti-PDA@SNP-OGP.The physical and chemical properties of Ti-PDA@SNP-OGP were assessed by scanning electron microscopy,X-ray photoelectron spectroscope,water contact angle,photothermal property and NO release behavior.The synergistic antibacterial effect and elimination of the MRSA biofilms were evaluated by 2′,7′-dichlorofluorescein diacetate probe,1-N-phenylnaphthylamine assay,adenosine triphosphate intensity,O-nitrophenyl-β-D-galactopyranoside hydrolysis activity,bicinchoninic acid leakage.Fluorescence staining,assays for alkaline phosphatase activity,collagen secretion and extracellular matrix mineralization,quantitative real‑time reverse transcription‑polymerase chain reaction,and enzyme-linked immunosorbent assay(ELISA)were used to evaluate the inflammatory response and osteogenic ability in bone marrow stromal cells(MSCs),RAW264.7 cells and their co-culture system.Giemsa staining,ELISA,micro-CT,hematoxylin and eosin,Masson's trichrome and immunohistochemistry staining were used to evaluate the eradication of MRSA biofilms,inhibition of inflammatory response,and promotion of osseointegration of Ti-PDA@SNP-OGP in vivo.Results:Ti-PDA@SNP-OGP displayed a synergistic photothermal and NO-dependent antibacterial effect against MRSA following near-infrared light(NIR)irradiation,and effectively eliminated the formed MRSA biofilms by inducing reactive oxygen species(ROS)-mediated oxidative stress,destroying bacterial membrane integrity and causing leakage of intracellular components(P<0.01).In vitro experiments revealed that Ti-PDA@SNP-OGP not only facilitated osteogenic differentiation of MSCs,but also promoted the polarization of pro-inflammatory M1 macrophages to the anti-inflammatory M2-phenotype(P<0.05 or P<0.01).The favorable osteo-immune microenvironment further facilitated osteogenesis of MSCs and the anti-inflammation of RAW264.7 cells via multiple paracrine signaling pathways(P<0.01).In vivo evaluation confirmed the aforementioned results and revealed that Ti-PDA@SNP-OGP induced ameliorative osseointegration in an MRSA-infected femoral defect implantation model(P<0.01).Conclusions:Ti-PDA@SNP-OGP is a promising multi-functional material for the high-efficient treatment of MRSA infections in implant replacement surgeries.

Floristic Diversity and Conservation Status of Guineo-Congolese Species in Southeastern Cameroon: The Case of the Gari-Gombo Communal Forest

The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rigor in the management of these forests, which can result in the loss of species of high conservation value. The study was carried out in communal forests in the south-east zone of Cameroon. Its aim was to carry out a floristic inventory and then compare the list of species with the IUCN catalog. Twenty-four plots, each with a surface area of 0.2 ha, were set up in the Gari-Gombo communal forest. All timbers with a DBH ≥ 5 cm were systematically counted. A total of 176 species, belonging to 144 genera and 45 families, were surveyed. Fabaceae (42.08%), Malvaceae (39%), Euphorbiaceae (24.64%), Moraceae (20.92%), Apocynaceae (18.64%), Cecropiaceae (16.60%), Ulmaceae (14.76%), Meliaceae (14.61%), Violaceae (14.08%), Combretaceae (12.67%), Theobroma cacao (21.17%), Baphia leptobotrys (18.06%), Rinorea sp. (14.09%), Musanga cecropioides (12.18%), Terminalia superba (10.32%), Neosloetiopsis kamerunensis (10.14%), Celtis zenkeri (8.29%) and Alstonia boonei (7.77%) were the most important taxa. Nearly 90% of the species in this forest are Guinean species, with a dominance of Guinean-Congolese species (66%). Fourteen (14) threatened species have been identified in the FCGG. This study, which highlights the rich biodiversity of communal forests, is important for guiding biodiversity conservation policies in ecosystems used for production.

Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM: To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.

Assessment of Nutritional Status and Associated Factors in Infants Aged 6 to 23 Months in Rural Burundi

This study was carried out in the Health districts of Kayanza and Gahombo. Its aim was to assess the nutritional status and associated factors of infants aged between 6 and 23 months. This descriptive and cross-sectional study was carried out in the health centers of the action zone during medical consultations in community medicine from 13 to 22 February 2023. For this purpose, 53.0% of a sample of 398 mothers of infants aged 6 - 23 months were male, and the most represented age group was 12 - 23 months with 53.8%. Mothers were asked about the diet of their children. All the children involved in this study were vaccinated, whereas 99.2% were given vitamin A supplements. The most frequent illnesses in this age group were acute respiratory infection (ARI) (73.4%), fever (66.6%), diarrhea (53.8%), and vomiting (40.5%). Analysis of nutritional status showed that infants had severe (8.3%) and moderate (70.4%) acute malnutrition. Factors associated with infant nutritional status comprised the occupation of mother (P = 0.009), level of education of mother (P = 0.0625), and prolonged diarrhea (P = 0.004). To remedy this problem, concrete nutritional and educational interventions are needed to promote optimal infant nutrition during the first two years of life.

EVOKED POTENTIALS OF OBSESSIVE-COMPULSIVE DISORDER:STATE OR TRAIT MARKER

Objective To investigate the status of evoked potentials in obsessive-compulsive disorder(OCD). Methods Evoked potentials P300, auditory brainstem response (ABR) and visual evoked potential ( VEP) were recorded from 35 OCD patients and 28 normal controls (NC) with a Nicolet Spirit Instrument. 23 of the OCD patients were followed up after 5 months with the same markers. Results Compared with NC, OCD patients showed decreased P3 of P300 amplitude (OCD group 3. 5 ±1. 6μv vs. NC group 5.9 ±2. 1μv, P <0. 01), delayed V latency (6.4±0. 4ms vs. 5. 5 ±0. 3ms, P <0. 01) and increased V amplitude(0. 35±0. 1μv vs. 0. 16 ±0.09μv, P <0. 05) of ABR and delayed P2 of VEP latency (199±39ms vs. 183±28ms, P <0. 05). The follow-up measures of evoked potentials suggested that decreased P3 of P300 amplitude and delayed P2 of VEP latency might be state markers of OCD, while decreased V amplitude and delayed V of ABR latency might be trait markers of OCD. Conclusion The changes of P300 and VEP are related to clinical status of OCD patients, while the association between ABR and OCD symptoms need to be further investigated.

Preceding Crops Selection, Colza Seeding Norms and Dates Optimization in North Kazakhstan

Colza is a relatively new crop for North Kazakhstan. The increase of colza seeds production is restricted by its cultivation technology imperfection. Empiric model of colza for seeds cultivation is designed, allowing using its maximum potential. It was found out that correct preceding crops selection, optimization of norms and dates of colza seeding provide seeds heavy weight crops, reducing crops production cost and increasing cost efficiency at 62% average.

Comprehensive comparison of cellulose nanocrystal (CNC) drying using multi-frequency ultrasonic technology with selected conventional drying technologies

Cellulose nanocrystals(CNCs)have garnered increased attention due to their renewable nature,abundant feedstock availbility,and good mechanical properties.However,one of the bottlenecks for its commercial production is the drying process.Because of the low CNC concentrations in suspension after isolation,CNC drying requires the removal of a large amount of water to obtain dry products for the following utilization and saving shipping costs.A novel multi-frequency,multimode,modulated ultrasonic drying technology was developed for CNC drying to improve product quality,reduce energy consumption,and increase production rate.CNCs dried with dif-ferent drying technologies were characterized by Fourier transform infrared(FT-IR)spectra anal-ysis,X-ray diffraction(XRD)analysis,thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),and redispersibility to measure the quality and property changes.Under the same temperature and airflow rate,ultrasonic drying enhanced drying rates,resulting in at least a 50%reduction in drying time compared to hot air drying.The mean particle sizes of CNC from ultrasonic drying changed little with settling time,indicating good redispersibility.In addition,ultrasonic dried CNCs exhibited good stability in aqueous solutions,with the zeta potentials rang-ing from-35 to-65 mV.Specific energy consumption and CO_(2) emissions of various CNC drying technologies were evaluated.Energy consumption of ultrasonic drying is significantly reduced compared to other drying technologies.Moreover,the potential CO_(2) emissions of the fully elec-trified ultrasonic drying could be net zero if renewable electricity is used.

DEGENERATE FOUR-WAVE MIXING FOR EXCITING STATES OF MOLECULES

Ⅰ. INTRODUCTION By using degenerate four-wave mixing (DFWM) method, the third-order nonlinear optical susceptibility of transparent media can be conventionally measured. Nonlinear properties of media in ground state are well known, but those in exciting state are less studied. When a medium absorbs incident radiation, a part of population can be excited into high exciting state. In DFWM this resonant enhancement effect can be used to increase the third-

Magnetic field-induced electronic phase transition in the Dirac semimetal state of black phosphorus under pressure

Different instabilities have been confirmed to exist in the three-dimensional(3D) electron gas when it is confined to the lowest Landau level in the extreme quantum limit. The recently discovered 3D topological semimetals offer a good platform to explore these phenomena due to the small sizes of their Fermi pockets, which means the quantum limit can be achieved at relatively low magnetic fields. In this work, we report the high-magnetic-field transport properties of the Dirac semimetal state in pressurized black phosphorus. Under applied hydrostatic pressure, the band structure of black phosphorus goes through an insulator-semimetal transition. In the high pressure topological semimetal phase, anomalous behaviors are observed on both magnetoresistance and Hall resistivity beyond the relatively low quantum limit field, which is demonstrated to indicate the emergence of an exotic electronic state hosting a density wave ordering. Our findings bring the first insight into the electronic interactions in black phosphorus under intense field.

China's Practice in Improving Tax Environment:An Exclusive Interview with Commissioner Wang Jun of STA,China

The United Nations Conference on Trade and Development(UNCTAD)has just released the World Investment Report 2021.According to the report,China remains the world’s second largest recipient of foreign direct investment(FDI),with its FDI inflows increasing by 6%over the previous year to US$149 billion in 2020,against the backdrop of a significant drop in global FDI inflows due to the COVID-19 epidemic.

经济不确定性对金融市场的影响机理——基于时变风险偏好视角

本文运用时变参数向量自回归(TVP-VAR)模型考察宏观不确定性和经济政策不确定性对金融市场的影响,并从时变风险偏好视角出发揭示该影响的机理。结果显示,经济不确定性对股票市场的影响最大,其次是货币市场,债券市场受到的影响最小;宏观不确定性主要通过“流动性偏好”渠道、“流动性资产转移”渠道、“错失恐惧”渠道影响金融资产价格变动,在宏观不确定性处于低于预期的高波动区间和宏观不确定性较高时,“流动性偏好”渠道在即期发挥的作用和“流动性资产转移”渠道、“错失恐惧”渠道在远期发挥的作用较大;经济政策不确定性主要通过“流动性资产转移”渠道和“安全资产转移”渠道影响金融资产价格变动,2008年后,在经济政策不确定性较低时,这两种渠道在即期发挥的作用较大。

新时代国家机关深化政治机关建设的理论逻辑与实践要求

深化政治机关建设,首先必须明确政治机关的实质意涵、使命担当等基本问题。我国的各级各类国家机关是受党和人民的委托、执掌国家权力的机关,承担着巩固党的领导地位和人民主体地位、贯彻党和人民的主张和意志、发展最广大人民根本利益的政治贵任和使命,因此,它们本质上都是政治机关。新时代国家机关深化政治机关建设的实践要求主要有:贯彻党和人民最根本的意志;坚定马克思主义政治信仰;站稳服务人民政治立场;把准中国特色社会主义政治方向;强化管党治党政治担当;坚守“两个维护”政治原则。

基于工程钻孔资料的V_(S30)估算新型模型

地表以下30 m深度的平均剪切波速(V_(S30))是评价场地条件及场地地震影响的重要参数。我国存在大量深度小于30 m的钻孔数据,此类钻孔无法直接计算得到V_(S30),阻碍了V_(S30)相关研究成果的推广应用,因此准确估算V_(S30)尤为重要。基于陕西关中平原4个城市590个孔深大于30 m的钻孔测井数据,采用拟合、对比方法开展V_(S30)估算模型研究。研究发现:钻孔不同深度的平均剪切波速(深度Z<30 m)及孔口高程与实算V_(S30)沿深度呈现较强的对数线性相关性,并由此提出了基于钻孔不同深度平均剪切波速及孔口高程的V_(S30)估算对数线性外推新型模型,简称双因素影响外推估算模型。相比速度梯度、双深度参数模型,在计算深度取值越小时,新型模型估算精度越高,稳定性越好,优势越突出。

The role of singlet oxygen and hydroxyl radical in the photobleaching of meso-substituted cationic pyridyl porphyrins in the presence of folic acid

Using a photosensitizer(PS),light,and oxygen,photodynamic therapy creates cytotoxic reactive oxygen species,such as singlet oxygen(1O2),that kill cancer cells.Many cancer cell lines have up to 300 times more folic acid receptors than healthy cells.Therefore,folic acid is often used to improve selectivity of PSs.Photobleaching poses a disadvantage for PSs.In this paper,we have studied the photoinduced changes of meso-substituted cationic pyridyl porphyrins in the presence of folic acid using uorescence and absorption spectroscopy.In this work,it was demonstrated that L-histidine,which is a 1O2 quencher,and D-mannitol,which is a hydroxyl radical quencher,can reduce photobleaching of cationic porphyrins and their interaction products with FA.This implies both singlet oxygen and hydroxyl radicals are involved in photobleaching.Additionally,our study revealed certain important features of the photobleaching of cationic porphyrins in the presence of folic acid.

职业院校课程思政调查分析与改进研究——以天津城市职业学院(南开分院)为例

课程思政建设应立足“立德树人”的根本任务,在拓展知识广度的同时,增加思政的深度和育人的温度。通过调查课程日志、发放问卷及访谈等形式,对本校教师课程思政意识及实践情况进行调查,针对教师在课程思政实践中面临的主要问题提出改进对策:由外及内的思想政治素质提升,自顶而下的示范性引领、协同育人的共育机制的建立。

Management of Severely Malnourished Children Aged 6 - 59 Months Hospitalized in the Pediatric Ward of Kayanza Hospital/Burundi

The implementation of WHO guidelines has significantly reduced hospital mortality due to severe malnutrition. Nevertheless, severe acute malnutrition in children under five remains a major public health problem in all low-income countries and is little studied. The study aimed to assess the nutritional status and quality of management of severe acute malnutrition in children aged 06 to 59 months hospitalized in the pediatric ward of Kayanza Hospital. This is a prospective study with descriptive and analytical aims over 6 months from February 10 to July 9, 2023. All children aged 6 to 59 months admitted for severe acute malnutrition are included in this study. The results show that the most affected age group is 12 to 23 months (42.55%). Marasmus is the most common clinical form, at 70.2%. Housewives and mothers from rural areas are the most affected, with rates ranging from 69.14% to 91.49%. The study shows that the reasons for consultation are respectively: edema (29.78%), diarrhea (26.59%), vomiting (19.14%), and fever (14.89%). Dehydration and hypothermia were the main complications observed in 45.74% and 22.34% respectively. Medical treatment was provided by antibiotics (44.68%), artesunate (31.91%), and resomal (21.27%). Nutritional treatment consisted of F75 100% milk and F100 100% milk. Pathologies observed were: anemia 38.29%, malaria 37.23%, urinary tract infection 12.7%, measles 11.7%. The national protocol for integrated management of acute malnutrition (PCIMA) was followed. This study shows that 72.3% of children were successfully treated, with 9.5% dropping out and dying, and 8.5% not responding. We found that malnutrition remains a public health problem, affecting mostly children aged 12 to 24 months. The main complications or pathologies associated with malnutrition are diarrhea, malaria, and fever, and the majority of children suffer from marasmus.

Enhancing Learners’Performance in Grade 7 Mathematics Through 50-30-20 Exercise

Assessment exercises constitute a crucial component of the teaching and learning process,serving the purpose of gauging the degree to which learning objectives have been accomplished.This study aims to assess the mathematics performance of Grade 7 learners using the 50-30-20 exercise.Specifically,this study seeks to determine the learners’pre-test and post-test mean scores,identify significant differences between the pre-test and post-test results,evaluate learners’exercises,and propose enhanced exercises.The research employs a quasi-experimental design,with 40 Grade 7 learners in the school year 2023-2024 as participants,selected through purposive non-random sampling.Statistical data analysis involves the use of mean,standard deviation,paired t-test,and Cohen’s D effect size.Ethical considerations were paramount,as evidenced by a letter of authorization from the school head outlining the strict adherence to voluntary participation,informed parental consent,anonymity,confidentiality,risk mitigation,results-sharing protocols,and the commitment to keeping research data confidential.The data yielded a remarkable outcome:the experimental group exhibited improvement in both the pre-test and post-test.This result substantiates the initial objective of the study,showcasing a noteworthy and favorable performance among the participants.Consequently,it suggests that a majority of the participants strongly agree that the 50-30-20 exercises contribute to enhancing their understanding and problem-solving skills,as well as their ability to grasp mathematical concepts and improve their overall performance in mathematics.Therefore,the 50-30-20 exercises not only facilitated students in understanding mathematics lessons but were also aligned with the Department of Education’s development plan.

浅谈马克笔在欧美及国内的安全标准

近年来,我国马克笔总的出口量和出口创汇值继续呈一定幅度的增长态势,但在出口过程中,因国内的安全标准与国外的安全标准差异较大,我国笔类企业遭受到越来越多的技术性贸易壁垒。安全标准是技术性贸易措施的主要内容之一,加强对笔类产品安全标准的研究,对解决国外技术贸易壁垒问题具有重要意义。

论述水性颜料墨水在斧头型笔头马克笔的应用

通过对水性颜料墨水的发展历程及其在马克笔产品中的应用现状进行综述,提出了可用于斧头型笔头的水性颜料墨水的研究思路和方法,并对其应用效果进行测试和评估。本文总结了研究成果,并提出了下一步的研究方向。

黑土区连作大豆根际微生物群落结构的动态变化

为探明长期连作对大豆根际土壤微生物群落结构的影响,基于环境因子相同的黑土区大豆连作长期定位试验,采用实时定量聚合酶链式反应(Quantity-PCR,qPCR)和PCR-DGGE技术,解析大豆根际微生物群落丰度和结构组成在不同连作年限间的动态变化过程。结果表明,连作7年以上处理的细菌群落结构组成和多样性明显低于轮作和连作4年以下处理,由此可以看出,大豆连续种植导致土壤中细菌群落组成的演替,是根际作物-土壤-微生物相互作用缓慢累积的过程,直到连作7年才足以被检测出来。连作大豆根际真菌群落结构多样性分析结果表明,连作2年和连作4年根际真菌群落组成丰富,多样性较高。而连作7年以上和轮作处理的大豆根际真菌群落多样性指数为3. 067 7~3. 071 5,低于连作2年和连作4年处理,同时连作7年处理真菌群落组成与轮作处理相似性较高,由此可以看出大豆连作土壤被称作抑制性土壤的机制所在。