Microwave-assisted exploration of the electron configuration-dependent electrocatalytic urea oxidation activity of 2D porous NiCo_(2)O_(4) spinel

Urea holds promise as an alternative water-oxidation substrate in electrolytic cells.High-valence nickelbased spinel,especially after heteroatom doping,excels in urea oxidation reactions(UOR).However,traditional spinel synthesis methods with prolonged high-temperature reactions lack kinetic precision,hindering the balance between controlled doping and highly active two-dimensional(2D)porous structures design.This significantly impedes the identification of electron configuration-dependent active sites in doped 2D nickel-based spinels.Herein,we present a microwave shock method for the preparation of 2D porous NiCo_(2)O_(4)spinel.Utilizing the transient on-off property of microwave pulses for precise heteroatom doping and 2D porous structural design,non-metal doping(boron,phosphorus,and sulfur)with distinct extranuclear electron disparities serves as straightforward examples for investigation.Precise tuning of lattice parameter reveals the impact of covalent bond strength on NiCo_(2)O_(4)structural stability.The introduced defect levels induce unpaired d-electrons in transition metals,enhancing the adsorption of electron-donating amino groups in urea molecules.Simultaneously,Bode plots confirm the impact mechanism of rapid electron migration caused by reduced band gaps on UOR activity.The prepared phosphorus-doped 2D porous NiCo_(2)O_(4),with optimal electron configuration control,outperforms most reported spinels.This controlled modification strategy advances understanding theoretical structure-activity mechanisms of high-performance 2D spinels in UOR.

Microwave shock motivating the Sr substitution of 2D porous GdFeO_(3) perovskite for highly active oxygen evolution

The incorporation of partial A-site substitution in perovskite oxides represents a promising strategy for precisely controlling the electronic configuration and enhancing its intrinsic catalytic activity.Conventional methods for A-site substitution typically involve prolonged high-temperature processes.While these processes promote the development of unique nanostructures with highly exposed active sites,they often result in the uncontrolled configuration of introduced elements.Herein,we present a novel approach for synthesizing two-dimensional(2D)porous GdFeO_(3) perovskite with A-site strontium(Sr)substitution utilizing microwave shock method.This technique enables precise control of the Sr content and simultaneous construction of 2D porous structures in one step,capitalizing on the advantages of rapid heating and cooling(temperature~1100 K,rate~70 K s^(-1)).The active sites of this oxygen-rich defect structure can be clearly revealed through the simulation of the electronic configuration and the comprehensive analysis of the crystal structure.For electrocatalytic oxygen evolution reaction application,the synthesized 2D porous Gd_(0.8)Sr_(0.2)FeO_(3) electrocatalyst exhibits an exceptional overpotential of 294 mV at a current density of 10 mA cm^(-2)and a small Tafel slope of 55.85 mV dec^(-1)in alkaline electrolytes.This study offers a fresh perspective on designing crystal configurations and the construction of nanostructures in perovskite.

Recent advances in design of hydrogen evolution reaction electrocatalysts at high current density:A review

The electrolysis of water powered by renewable energy sources offers a promising method of"green hydrogen"production,which is considered to be at the heart of future carbon-neutral energy systems.In the past decades,researchers have reported a number of hydrogen evolution reaction(HER)electrocatalysts with activity comparable to that of commercial Pt/C,but most of them are tested within a small current density range,typically no more than 500 mA cm^(-2).To realize the industrial application of hydrogen production from water electrolysis,it is essential to develop high-efficiency HER electrocatalysts at high current density(HCD≥500 mA cm^(-2)).Nevertheless,it remains challenging and significant to rational design HCD electrocatalysts for HER.In this paper,the design strategy of HCD electrocatalysts is discussed,and some HCD electrocatalysts for HER are reviewed in seven categories(alloy,metal oxide,metal hydroxide,metal sulfide/selenide,metal nitride,metal phosphide and other derived electrocatalysts).At the end of this article,we also pro-pose some viewpoints and prospects for the future development and research directions of HCD electrocatalysts for HER.

肠碱性磷酸酶在肠黏膜屏障中的作用

肠碱性磷酸酶(intestinal alkaline phosphatase,IAP)是一种碱性磷酸酶,在维持肠黏膜屏障的稳定和肠道功能具有重要作用,其中包括调节十二指肠pH、反映肠道的发育情况及小肠上皮细胞的吸收能力,降低肠道脂多糖毒力、预防和减少肠道炎症、调节肠道菌群分布、抑制细菌位移、改善肠道钙吸收等功能.本文对近年来IAP在肠黏膜屏障中的作用研究进展做一综述.

低含量含砷水暴露对子代鼠生长和发育的影响

目的探讨饮水中低含量砷对小鼠生长和发育的影响。方法小鼠交配受孕后,给予洁净水(对照组)或10μg/L砷水(砷暴露组)饲养小鼠,评价母鼠生产结果、第1代幼鼠生长及健康状况。结果对照组和砷暴露组产仔数、孕龄及幼崽(包括存活和死亡)出生重量比较,差异无统计学意义(P>0.05)。出生后10和22天砷暴露组子代鼠体重低于对照组(P<0.05),表明出生后砷暴露组子代鼠生长发育减缓。妊娠第15.5天时,砷暴露组母鼠脂肪肝发生率为55.5%(5/9)高于对照组的0.0%(0/9)(P<0.05)。结论母鼠及其第1代子鼠暴露于低含量含砷水(含量符合我国当前饮用水标准)对第1代子鼠的关键生长发育期产生不良影响。

Mesenchymal stem cells alleviate TNBS-induced colitis by modulating inflammatory and autoimmune responses

AIM: To investigate the potential therapeutic effects of mesenchymal stem cells (MSCs) in inflammatory bowel disease (IBD), we transplanted MSCs into an experimental model of IBD. METHODS: A rectal enema of trinitrobenzene sulfonic acid (TNBS) (100 mg/kg body weight) was administered to female BALB/c mice. Bone marrow mesenchymal stem cells (BMSCs) were derived from male green fluorescent protein (GFP) transgenic mice and were transplanted intravenously into the experimental animals after disease onset. Clinical activity scores and histological changes were evaluated. GFP and Sex determining region Y gene (SRY ) expression were used for cell tracking. Ki67 positive cells and Lgr5-expressing cells were determined to measure proliferative activity. Inflammatory response was determined by mea-suring the levels of different inflammatory mediators in the colon and serum. The inflammatory cytokines included tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-6, IL-17, IL-4, IL-10, and transforming growth factor (TGF-β). Master regulators of Th1 cells (T-box expressed in T cells, T-bet), Th17 cells (retinoid related orphan receptor gamma(t), RORγt), Th2 cells (GATA family of transcription factors 3, GATA3) and regulatory T cells (forkhead box P3, Foxp3) were also determined. RESULTS: Systemic infusion of GFP-BMSCs ameliorated the clinical and histopathologic severity of colitis, including body weight loss, diarrhea and inflammation, and increased survival (P < 0.05). The cell tracking study showed that MSCs homed to the injured colon. MSCs promoted proliferation of intestinal epithelial cells and differentiation of intestinal stem cells (P < 0.01). This therapeutic effect was mainly mediated by downregulation of both Th1-Th17-driven autoimmune and inflammatory responses (IL-2, TNF-α, IFN-γ, T-bet; IL-6, IL-17, RORγt), and by up-regulation of Th2 activities (IL-4, IL-10, GATA-3) (P < 0.05). MSCs also induced activated CD4 + CD25 + Foxp3 + regulatory T cells (TGF-β, IL-10, Foxp3) with a suppressive capacity on Th1-Th17 effecter responses and promoted Th2 differentiation in vivo (P < 0.05). CONCLUSION: MSCs are key regulators of immune and inflammatory responses and may be an attractive candidate for cell-based therapy of IBD.

Oxymatrine liposome attenuates hepatic fibrosis via targeting hepatic stellate cells

AIM： To investigate the potential mechanism of Arg- Gly-Asp （RGD） peptide-labeled liposome loading oxy- matrine （OM） therapy in CCI4-induced hepatic fibrosis in rats. METHODS： We constructed a rat model of CCh- induced hepatic fibrosis and treated the rats with dif- ferent formulations of OM. To evaluate the antifibrotic effect of OM, we detected levels of alkaline phospha- tase, hepatic histopathology （hematoxylin and eosin stain and Masson staining） and fibrosis-related gene expression of matrix metallopeptidase （MMP）-2, tis- sue inhibitor of metalloproteinase （TIMP）-I as well as type I procollagen via quantitative real-time poly- merase chain reaction. To detect cell viability and apop- tosis of hepatic stellate cells （HSCs）, we performed 3-（4,5）-dimethylthiahiazo（-z-yl）-3,5-diphenytetrazoli- umromide assay and flow cytometry. To reinforce the combination of oxymatrine with HSCs, we constructed fluorescein-isothiocyanate-conjugated Arg-Gly-Asp peptide-labeled liposomes loading OM, and its targeting of HSCs was examined by fluorescent microscopy. RESULTS： OM attenuated CCh-induced hepatic fibro- sis, as defined by reducing serum alkaline phosphatase （344.47± 27.52 U/L vs 550.69 ± 43.78 U/L, P 〈 0.05）, attenuating liver injury and improving collagen deposits （2.36% ± 0.09% vs 7.70% ±0.60%, P 〈 0.05） and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen （P 〈 0.05）. OM inhibited cell viability and induced apoptosis of HSCs in vitro. RGD promoted OM targeting of HSCs and en- hanced the therapeutic effect of OM in terms of serum alkaline phosphatase （272.51 ± 19.55 U/L vs 344.47 ± 27.52 U/L, P 〈 0.05）, liver injury, collagen deposits （0.26%± 0.09% vs 2.36% ± 0.09%, P 〈 0.05） and downregulating fibrosis-related gene expression, that is, MMP-2, TIMP-1 and type I procollagen （P 〈 0.05）. Moreover, in vitro assay demonstrated that RGD en- hanced the effect of OM on HSC viability and apoptosis. CONCLUSION： OM attenuated hepatic fibrosis by in- hibiting viability and inducing apoptosis of HSCs. The RGD-labeled formulation enhanced the targeting effi- ciency for HSCs and the therapeutic effect.

Classification,clinicopathologic features and treatment of gastric neuroendocrine tumors

Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by hypergastrinemia that arise from enterochromaffin-like cells of the stomach. GNETs consist of a heterogeneous group of neoplasms comprising tumor types of varying pathogenesis, histomorphologic characteristics, and biological behavior. A classification system has been proposed that distinguishes four types of GNETs; the clinicopathological features of the tumor, its prognosis, and the patient&#x02019;s survival strictly depend on this classification. Thus, correct management of patients with GNETs can only be proposed when the tumor has been classified by an accurate pathological and clinical evaluation of the patient. Recently developed cancer therapies such as inhibition of angiogenesis or molecular targeting of growth factor receptors have been used to treat GNETs, but the only definitive therapy is the complete resection of the tumor. Here we review the literature on GNETs, and summarize the classification, clinicopathological features (especially prognosis), clinical presentations and current practice of management of GNETs. We also present the latest findings on new gene markers for GNETs, and discuss the effective drugs developed for the diagnosis, prognosis and treatment of GNETs.

微波热冲快速制备二维多孔La_(0.2)Sr_(0.8)CoO_(3)钙钛矿用于高效电催化析氧反应

析氧反应(OER)被认为是电解水的关键限制步骤,已被广泛作为清洁能源方式用于解决能源和环境问题。钙钛矿氧化物(ABO_(3))具有可调的电子结构、高灵活性的元素组成,能在OER中表现出良好的催化活性。然而,钙钛矿氧化物的合成通常需要经历长时间的高温,极易导致金属的聚集和影响材料的本征活性。气相微波技术可以显著缩短热处理时间,从而减少相关的碳排放。这项技术不仅解决了对碳中性过程日益增长的需求,而且还增加了对合成的控制,以避免产品的不良团聚。本文采用微波热冲法快速制备了二维(2D)多孔La_(0.2)Sr_(0.8)CoO_(3)钙钛矿。伴随微波过程的快速熵增可以有效地暴露La_(0.2)Sr_(0.8)CoO_(3)结构中丰富的活性位点。此外,高能微波冲击过程可以精准地将Sr2+引入到LaCoO_(3)的晶格中,通过增加Co的氧化态来增加氧空位量。这种锶元素取代镧引入的氧空位能极大提高催化剂的本征催化活性。对于碱性电解液中的OER应用,制备的La_(0.2)Sr_(0.8)CoO_(3)在10 m A·cm^(-2)下展现出了360 m V的过电位,Tafel斜率为76.6 mV·dec^(-1)。且在经历30000秒的长时间循环测试后仍能维持初始电流密度的97%。这项研究为高活性二维钙钛矿的合成提供了一种简便、快速的策略。

Analytical optimization on GNSS buoy array for underwater positioning

Global navigation satellite system(GNSS)/acoustic positioning precision is determined by the positioning geometry and the ranging precision;thus optimizing GNSS buoys array is meaningful to improve the positioning accuracy and reliability.An analytical method is proposed for optimizing the GNSS buoys array with regard to the cutoff angle constraints for underwater acoustic observations.For the practical limitation of coplanarity of GNSS buoys and the cutoff angle,an algorithm is proposed to analytically minimize the position dilution of precision(PDOP).The proposed method is validated to give complete solutions of PDOP minimization with five GNSS buoys.At last,in order to search a best configuration among the PDOP solution set,we propose a search algorithm to get the solution with the smallest geometric dilution of precision(GDOP).It indicates that within a given region,the GDOP minimization at the center of a region is equivalent to the PDOP mean minimization over the region.The relation between the positioning accuracy and the positioning geometry with five known points is illustrated in an experiment performed in South China Sea.

Rare case of Helicobacter pylori -related gastric ulcer: Malignancy or pseudomorphism?

Helicobacter pylori (H. pylori ) is a pathogen and the most frequent cause of gastric ulcers. There is also a close correlation between the prevalence of H. pylori infection and the incidence of gastric cancer. We present the case of a 38-year-old woman referred by her primary care physician for screening positron emission tomography-computed tomography (PET-CT), which showed a nodular strong accumulation point with standardized uptake value 5.6 in the gastric fundus. Gastroscopy was then performed, and a single arched ulcer, 12 mm in size, was found in the gastric fundus. Histopathological examination of the lesion revealed chronic mucosal inflammation with acute inflammation and H. pylori infection. There was an obvious mitotic phase with widespread lymphoma. Formal anti-H. pylori treatment was carried out. One month later, a gastroscopy showed a single arched ulcer, measuring 10 mm in size in the gastric fundus. Histopathological examination revealed chronic mucosal inflammation with acute inflammation and a very small amount of H. pylori infection. The mitotic phase was 4/10 high power field, with some heterotypes and an obvious nucleolus. Follow-up gastroscopy 2 mo later showed the gastric ulcer in stage S2. The mucosal swelling had markedly improved. The patient remained asymptomatic, and a follow-up PET-CT was performed 6 mo later. The nodular strong accumulation point had disappeared. Follow-up gastroscopy showed no evidence of malignant cancer. H. pylori-associated severe inflammation can lead to neoplastic changes in histiocytes. This underscores the importance of eradicating H. pylori , especially in those with mucosal lesions, and ensuring proper follow-up to prevent or even reverse early gastric cancer.

Growth inhibitory effect of wild-type Kras2 gene on a colonic adenocarcinoma cell line

AIM： To observe the growth inhibitory effect of wild-type Kras2 gene on a colonic adenocarcinoma cell line Caco-2. METHODS： Recombinant plasmid pCI-neo-Kras2 with wild type Kras2 open reading frame was constructed. The Caco-2 cells were transfected with either pCI-neo or pCI-neo-Kras2 using Upofectamine 2000. The expression of wild type Kras2 was examined by Northern blot analysis. And the expression of wild type Kras2 protein was examined by Western blot analysis. The effects of wild-type Kras2 on cell proliferation were analyzed by monotetrazolium （MTT） assay, meanwhile analyses of cell cycle and spontaneous apoptosis rate were carried out by flow cytometry （FCM）. RESULTS： The plasmid of pCI-neo-Kras2 was successfully established. The growth rate of cells transfected with pCI-neo-Kras2 was significantly lower than the control cells transfected with the empty pCI- neo vector （P 〈 0.05）. Cell cycle analysis revealed arrest of the pCI-neo-Kras2 transfected cells in G0/G1 phases, decreased DNA synthesis and decreased fractions of cells in S phase. The proliferative index of cells transfected with pCI-neo-Kras2 was decreased compared with the control cells （49.78% vs 64.21%）, while the apoptotic rate of Caco-2 cells with stable Kras2 expression increased （0.30% vs 0.02%）. CONCLUSION： The wild-type Kras2 gene effectively inhibits the growth of the colonic adenocarcinoma cell line Caco-2.

Loss of heterozygosity of Kras2 gene on 12p12-13 in Chinese colon carcinoma patients

AIM： To study the loss of heterozygosity （LOH） on 12p12-13 in Chinese colon carcinoma patients.METHODS： DNA was extracted from 10 specimens of cancer tissue, 10 specimens of adjacent tissue and 10 specimens of normal tissue, respectively. LOH of Kras2 gene was analyzed by polymerase chain reaction （PCR） and denaturing polyacrylamide gel electrophoresis using 11 microsatellite markers on 12p-12-13.RESULTS： LOH of Kras gene was detected at least on one marker of 12p-12-13 in 30% （3/10） of adjacent tissue specimens. The highest frequency of LOH was identified on D12S1034 in 28.57% （2]7） of adjacent tissue specimens. LOH was detected at least on one marker of 12p12-13 in 60% （6/10） of carcinoma tissue specimens, the most frequent LOH was found on D12S1034 and D12S1591 in 42.86% （3/7） of carcinoma tissue specimens. LOH was detected in 30% （3/10） of carcinoma tissue specimens, 30% （3/10） of adjacent tissue specimens, and no signal in 1% （1/0） carcinoma tissue specimen. The occurrence of LOH did not correlate with sex, age, tumor size and lymph node metastasis.CONCLUSION： Genomic instability may occur on 12p-12-13 of Kras2 gene in the development and progression of colon carcinoma. The high LOH of Kras2 gene may directly influence the transcription and translation of wild type Kras2 gene.

Proportions of acetyl-histone-positive hepatocytes indicate the functional status and prognosis of cirrhotic patients

AIM:To investigate whether the proportions of acetylhistone-positive hepatocytes could be used as markers of deteriorating liver function.METHODS:In total,611 cirrhotic cases from 3701 patients who were diagnosed during the past 15 years were screened,and 152 follow-up cases were selected.Paraffin tissue microarray was prepared for immunohistochemistry to examine acetyl-histone expression.The proportions of positive hepatocytes were recorded,and their correlations to clinical and laboratory indicators were analyzed statistically.RESULTS:The proportions of H2AK5ac+,H3K9/K14ac+ and H3K27ac+ hepatocytes gradually increased with deteriorating liver function and with increasing levels of serum markers of liver injury.In the follow-up cases,patients with > 70% H2AK5ac+,H3K9/K14ac+ or H3K27ac+ hepatocytes had statistically lower survival rates(P < 0.05).Furthermore,> 70% H2AK5ac+ or H3K27ac+ hepatocytes were strong independent predictors of overall survival(P < 0.05).CONCLUSION:The proportions of acetyl-histonepositive hepatocytes are closely associated with the liver function and prognosis of cirrhotic patients.

Enhancing an internal electric field by a solid solution strategy for steering bulk-charge flow and boosting photocatalytic activity of Bi_(24)O_(31)Cl_(x)Br_(10-x)

Constructing bismuth oxyhalide solid solutions with a single homogeneous phase have intrigued the research community;however,a deeper understanding of the intrinsic origin for improved bulk-charge separation is still unclear.Herein,a series of Bi_(24)O_(31)Cl_(x)Br_(10-x) solid solutions with the same structural characteristics were synthesized by crystal structure regulation.Combining density functional theory calculation,Kelvin probe force microscopy,and zeta potential testing results,an enhanced internal electric field(IEF)intensity between[Bi_(24)O_(31)]and[X]layers was achieved by changing halogen types and ratios.This greatly facilitated bulk-charge separation and transfer efficiency,which is significant for the degradation of phenolic organic pollutants.Owing to the enhanced IEF intensity,the charge carrier density of Bi_(24)O_(31)Cl_(4)Br_(6) was 33.1 and 4.7 times stronger than that of Bi_(24)O_(31)Cl_(10) and Bi_(24)O_(31)Br_(10),respectively.Therefore,Bi24O31Cl4Br6 had an optimal photoactivity for the degradation of bisphenol A,which was 6.21 and 2.71 times higher than those of Bi_(24)O_(31)Cl_(10) and Bi_(24)O_(31)Br_(10),respectively.Thus,this study revealed the intrinsic mechanism of the solid solution strategy for photocatalytic performance enhancement with respect to an IEF.

Role of serum carcinoembryonic antigen in the detection of colorectal cancer before and after surgical resection

AIM:To determine whether serum levels of carcinoembryonic antigen(CEA) correlate with the presence of primary colorectal cancer(CRC),and/or recurrent CRC following radical resection.METHODS:A total of 413 patients with CRC underwent radical surgery between January 1998 and December 2002 in our department and were enrolled in this study.The median follow-up period was 69 mo(range,3-118 mo),and CRC recurrence was experienced by 90/413(21.8%) patients.Serum levels of CEA were assayed preoperatively,and using a cutoff value of 5 ng/mL,patients were divided into two groups,those with normal serum CEA levels(e.g.,≤ 5 ng/mL) and those with elevated CEA levels(> 5 ng/mL).RESULTS:The overall sensitivity of CEA for the detection of primary CRC was 37.0%.The sensitivity of CEA according to stage,was 21.4%,38.9%,and 41.7% for stagesⅠ-Ⅲ,respectively.Moreover,for stageⅡandstageⅢcases,the 5-year disease-free survival rates were reduced for patients with elevated preoperative serum CEA levels(P < 0.05).The overall sensitivity of CEA for detecting recurrent CRC was 54.4%,and sensitivity rates of 36.6%,66.7%,and 75.0% were associated with cases of local recurrence,single metastasis,and multiple metastases,respectively.In patients with normal serum levels of CEA preoperatively,the sensitivity of CEA for detecting recurrence was reduced compared with patients having a history of elevated CEA prior to radical resection(32.6% vs 77.3%,respectively,P < 0.05).CONCLUSION:CRC patients with normal serum CEA levels prior to resection maintained these levels during CRC recurrence,especially in cases of local recurrence vs cases of metastasis.

Osteocyte Egln1/Phd2 links oxygen sensing and biomineralization via FGF23

Osteocytes act within a hypoxic environment to control key steps in bone formation.FGF23,a critical phosphate-regulating hormone,is stimulated by low oxygen/iron in acute and chronic diseases,however the molecular mechanisms directing this process remain unclear.Our goal was to identify the osteocyte factors responsible for FGF23 production driven by changes in oxygen/iron utilization.Hypoxia-inducible factor-prolyl hydroxylase inhibitors(HIF-PHI)which stabilize HIF transcription factors,increased Fgf23 in normal mice,as well as in osteocyte-like cells;in mice with conditional osteocyte Fgf23 deletion,circulating i FGF23 was suppressed.An inducible MSC cell line(‘MPC2’)underwent FG-4592 treatment and ATACseq/RNAseq,and demonstrated that differentiated osteocytes significantly increased HIF genomic accessibility versus progenitor cells.Integrative genomics also revealed increased prolyl hydroxylase Egln1(Phd2)chromatin accessibility and expression,which was positively associated with osteocyte differentiation.In mice with chronic kidney disease(CKD),Phd1-3 enzymes were suppressed,consistent with FGF23 upregulation in this model.Conditional loss of Phd2 from osteocytes in vivo resulted in upregulated Fgf23,in line with our findings that the MPC2 cell line lacking Phd2(CRISPR Phd2-KO cells)constitutively activated Fgf23 that was abolished by HIF1αblockade.In vitro,Phd2-KO cells lost iron-mediated suppression of Fgf23 and this activity was not compensated for by Phd1 or-3.In sum,osteocytes become adapted to oxygen/iron sensing during differentiation and are directly sensitive to bioavailable iron.Further,Phd2 is a critical mediator of osteocyte FGF23 production,thus our collective studies may provide new therapeutic targets for skeletal diseases involving disturbed oxygen/iron sensing.

Zeolitic imidazolate framework-8 as a nanoadsorbent for radon capture

The feasibility of adsorption and the adsorption behavior of radon on a nanomaterial-based zeolitic imidazolate framework-8(ZIF-8) adsorbent were investigated.Grand canonical Monte Carlo simulation and four-channel low-background a/b measurement were performed to examine the adsorption kinetics of this adsorbent. Results demonstrated that ZIF-8 is a good adsorbent of radon.Therefore, this adsorbent can be used to significantly reduce the hazardous effects of radon on occupational radiation workers.

Epiphyseal distraction and hybrid reconstruction using polymethyl methacrylate construct combined with free non-vascularized fibular graft in pediatric patients with osteosarcoma around knee: A case report

BACKGROUND In children with osteosarcoma around the knee joint without epiphysis involvement,joint-sparing surgery seems to be an ideal way to retain knee joint function.However,there are two points of debate with regard to the technique:How to accurately achieve a safe surgical margin,and how to achieve intercalary reconstruction of the massive bone defect following resection of the tumor.CASE SUMMARY We present the case of an 8-year-old girl with osteosarcoma of the distal femur without involvement of the epiphysis.Epiphyseal distraction was applied to separate the epiphysis and metaphysis,and this provided a safe surgical margin.The massive bone defect was reconstructed with a custom-made antibioticloaded polymethyl methacrylate(PMMA)construct combined with a free nonvascularized fibular graft.Six months after surgery,bone union between the autograft and host bone was confirmed in both the proximal and distal femur by computer tomography(CT)examination.Moreover,considerable callus formation was found around the PMMA construct.After 28 mo of follow-up,there was no sign of recurrence or metastasis.The patient could walk without any aid and carry out her daily life activities satisfactorily.CONCLUSION In cases of osteosarcoma without epiphysis involvement,epiphyseal distraction can be easily applied to obtain a safe margin.Hybrid reconstruction with an antibiotic-loaded PMMA construct combined with a free non-vascularized fibular graft has the advantages of being easy to manufacture,less time-consuming to place,and less likely to get infected,while also ensuring bone union.Our case provides an alternative technique for biological reconstruction after joint-sparing surgery in patients with osteosarcoma around the knee without epiphyseal involvement.

Application of Polyurethane Curing Barn in Flue-cured Tobacco Production

[ Objective] This study aimed to investigate the curing performance of polyurethane curing barn and reduce the cost of tobacco leaf flue-curing. [ Meth- odl The temperature control effect, curing effect and curing cost of polyurethane curing barn and traditional bulk curing barn were analyzed and compared. [ Re- suit] The results showed that there were no significant differences in curing performance between two types of curing barns. Horizontal temperature differences in- creased slightly as the temperature rose. Specifically, horizontal temperature differences between each layer ranged from 0.2 ~C to 0.5 ~. Both two types of curing barns exhibited uniform air distribution. Polyurethane curing barn exhibited stable vertical temperature differences. Both two types of curing barns presented good curing effects with slight differences. Polyurethane curing barn exhibited higher economic benefits, lower coal cost, lower electricity cost, lower labor cost and lon- ger service life than traditional bulk curing barn, but its construction cost was higher. [ Conclusion] Polyurethane curing barn exhibits better curing performance with ~ood application prospects.