A novel live attenuated vaccine candidate protects chickens against subtype B avian metapneumovirus

Avian metapneumovirus(aMPV) is a highly contagious pathogen that causes acute upper respiratory tract diseases in chickens and turkeys, resulting in serious economic losses. Subtype B aMPV has recently become the dominant epidemic strain in China. We developed an attenuated aMPV subtype B strain by serial passaging in Vero cells and evaluated its safety and efficacy as a vaccine candidate. The safety test showed that after the 30th passage, the LN16-A strain was fully attenuated, as clinical signs of infection and histological lesions were absent after inoculation.The LN16-A strain did not revert to a virulent strain after five serial passages in chickens. The genomic sequence of LN16-A differed from that of the parent wild-type LN16(wtLN16) strain and had nine amino acid mutations. In chickens, a single immunization with LN16-A induced robust humoral and cellular immune responses, including the abundant production of neutralizing antibodies, CD4^(+) T lymphocytes, and the Th1(IFN-γ) and Th2(IL-4 and IL-6)cytokines. We also confirmed that LN16-A provided 100% protection against subtype B aMPV and significantly reduced viral shedding and turbinate inflammation. Our findings suggest that the LN16-A strain is a promising live attenuated vaccine candidate that can prevent infection with subtype B aMPV.

乙烯基封端型氧化石墨烯和碳纳米管复合聚氨酯UV固化树脂的合成与性能

为提高聚氨酯紫外光固化涂料的力学性能和导电性,基于聚氨酯化学反应,采用异佛尔酮二异氰酸酯(IPDI)和甲基丙烯酸羟乙酯(HEMA)对氧化石墨烯(GO)实现了化学接枝,制备出新型氧化石墨烯(HEMA@GO)。探讨了HEMA@GO和多壁碳纳米管(MWCNTs)协同复合对聚氨酯基UV固化涂层的机械强度和导电性的影响。结果表明:化学接枝型氧化石墨烯的层间距由接枝前的0.89 nm扩大到2.10 nm,改善了GO在聚氨酯基体中的分散能力和界面相互作用;当HEMA@GO和MWCNTs的添加量分别为1.0%、3.0%时,聚氨酯膜的拉伸强度和涂层硬度达到了最佳,分别为13.6 MPa和6H。此外,HEMA@GO和MWCNTs的协同作用,显著降低了聚氨酯涂层的方块电阻,从空白涂层的1012 kΩ/□降至7.1 kΩ/□,展现出优异的导电性和力学性能提升效果。

Multi-Scale Dilated Convolution Network for SPECT-MPI Cardiovascular Disease Classification with Adaptive Denoising and Attenuation Correction

Myocardial perfusion imaging(MPI),which uses single-photon emission computed tomography(SPECT),is a well-known estimating tool for medical diagnosis,employing the classification of images to show situations in coronary artery disease(CAD).The automatic classification of SPECT images for different techniques has achieved near-optimal accuracy when using convolutional neural networks(CNNs).This paper uses a SPECT classification framework with three steps:1)Image denoising,2)Attenuation correction,and 3)Image classification.Image denoising is done by a U-Net architecture that ensures effective image denoising.Attenuation correction is implemented by a convolution neural network model that can remove the attenuation that affects the feature extraction process of classification.Finally,a novel multi-scale diluted convolution(MSDC)network is proposed.It merges the features extracted in different scales and makes the model learn the features more efficiently.Three scales of filters with size 3×3 are used to extract features.All three steps are compared with state-of-the-art methods.The proposed denoising architecture ensures a high-quality image with the highest peak signal-to-noise ratio(PSNR)value of 39.7.The proposed classification method is compared with the five different CNN models,and the proposed method ensures better classification with an accuracy of 96%,precision of 87%,sensitivity of 87%,specificity of 89%,and F1-score of 87%.To demonstrate the importance of preprocessing,the classification model was analyzed without denoising and attenuation correction.

UV/Fe(Ⅲ)工艺对络合态重金属的去除效果及机理

UV/Fe(Ⅲ)工艺是一种处理络合态重金属的新型组合工艺,该工艺先通过Fe(Ⅲ)的置换作用释放游离重金属离子,然后通过UV辐照对有机配体进行降解,最后通过碱性沉淀去除络合态重金属。以Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA为目标污染物,采用UV/Fe(Ⅲ)工艺对其进行去除,通过去除效果对比和机理分析,对组合工艺去除效果差异的内部机理进行阐述,并提出相应的优化方案。结果表明,UV/Fe(Ⅲ)工艺对Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA的去除效果存在较大差异,对两种络合态重金属中Cu、Ni的去除率分别为70%和41%。通过高效液相色谱(HPLC)、分光光度法、苯甲酸(BA)探针实验,确定Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA去除效果差异的主要原因是Fe(Ⅲ)对Cu(Ⅱ)、Ni(Ⅱ)的置换效果有明显差异,置换率分别是85%、22%。对Ni(Ⅱ)-EDTA置换过程分别进行Fe(Ⅲ)投加量和反应温度优化,结果表明,反应温度优化可以显著提升Fe(Ⅲ)对Ni(Ⅱ)-EDTA的置换效率。将反应温度提升至35℃,Ni去除率从41%提升至60%。反应温度在UV/Fe(Ⅲ)工艺中对Ni(Ⅱ)-EDTA的去除至关重要,适当升温有助于提高置换率,进而提升去除率。

Evaluatingα-galactosylceramide as an adjuvant for live attenuated infuenza vaccines in pigs

Natural killer T(NKT)cells activated with the glycolipid ligandα-galactosylceramide(α-GalCer)stimulate a wide variety of immune cells that enhance vaccine-mediated immune responses.Several studies have used this approach to adjuvant inactivated and subunit infuenza A virus(IAV)vaccines,including to enhance cross-protective infuenza immunity.However,less is known about whetherα-GalCer can enhance live attenuated infuenza virus(LAIV)vaccines,which usually induce superior heterologous and heterosubtypic immunity compared to non-replicating infuenza vaccines.The current study used the swine infuenza challenge model to assess whetherα-GalCer can enhance cross-protective immune responses elicited by a recombinant H3N2 LAIV vaccine(TX98ΔNS1)encoding a truncated NS1 protein.In one study,weaning pigs were administered the H3N2 TX98ΔNS1 LAIV vaccine with 0,10,50,and 100μg/kg doses ofα-GalCer,and subsequently challenged with a heterologous H3N2 virus.All treatment groups were protected from infection.However,the addition ofα-GalCer appeared to suppress nasal shedding of the LAIV vaccine.In another experiment,pigs vaccinated with the H3N2 LAIV,with or without 50μg/kg ofα-GalCer,were challenged with the heterosubtypic pandemic H1N1 virus.Pigs vaccinated with the LAIV alone generated cross-reactive humoral and cellular responses which blocked virus replication in the airways,and signifcantly decreased virus shedding.On the other hand,combining the vaccine withα-GalCer reduced cross-protective cellular and antibody responses,and resulted in higher virus titers in respiratory tissues.These fndings suggest that:(i)high doses ofα-GalCer impair the replication and nasal shedding of the LAIV vaccine;and(ii)α-GalCer might interfere with heterosubtypic cross-protective immune responses.This research raise concerns that should be considered before trying to use NKT cell agonists as a possible adjuvant approach for LAIV vaccines.

Non-uniform electron density estimation based on electromagnetic wave attenuation in plasma

The surface of a high-speed vehicle reentering the atmosphere is surrounded by plasma sheath.Due to the influence of the inhomogeneous flow field around the vehicle,understanding the electromagnetic properties of the plasma sheath can be challenging.Obtaining the electron density of the plasma sheath is crucial for understanding and achieving plasma stealth of vehicles.In this work,the relationship between electromagnetic wave attenuation and electron density is deduced theoretically.The attenuation distribution along the propagation path is found to be proportional to the integral of the plasma electron density.This result is used to predict the electron density profile.Furthermore,the average electron density is obtained using a back-propagation neural network algorithm.Finally,the spatial distribution of the electron density can be determined from the average electron density and the normalized derivative of attenuation with respect to the propagation depth.Compared to traditional probe measurement methods,the proposed approach not only improves efficiency but also preserves the integrity of the plasma environment.

Laparoscopic hepatectomy using indocyanine green attenuates postoperative inflammatory response for hepatocellular carcinoma:A propensity score matching analysis

BACKGROUND Improving the intraoperative and postoperative performance of laparoscopic hepatectomy was quite a challenge for liver surgeons.AIM To determine the benefits of indocyanine green(ICG)fluorescence imaging in patients with hepatocellular carcinoma(HCC)who underwent laparoscopic hepatectomy during and after surgery.METHODS We retrospectively collected the clinicopathological data of 107 patients who successfully underwent laparoscopic hepatectomy at Zhongshan Hospital(Xiamen),Fudan University from June 2022 to June 2023.Whether using the ICG fluorescence imaging technique,we divided them into the ICG and non-ICG groups.To eliminate statistical bias,a 1:1 propensity score matching analysis was conducted.The comparison of perioperative outcomes,including inflammationrelated markers and progression-free survival,was analyzed statistically.RESULTS Intraoperatively,the ICG group exhibited lower blood loss,a shorter surgical time,lower hepatic inflow occlusion(HIO)frequency,and a shorter total HIO time.Postoperatively,the participation of ICG resulted in a shorter duration of hospitalization(6.5 vs 7.6 days,P=0.03)and postoperative inflammatory response attenuation(lower neutrophil-lymphocyte ratio on the first day after surgery and platelet-lymphocyte ratio on the third day,P<0.05).Although the differences were not significant,the levels of all inflammation-related markers were lower in the ICG group.The rates of postoperative complications and the survival analyses,including progression-free and overall survivals showed no significant difference between the groups.CONCLUSION The involvement of ICG fluorescence imaging may lead to improved perioperative outcomes,especially postoperative inflammatory response attenuation,and ultimately improve HCC patients’recovery after surgery.

Construction of Mutation Library in Haemophilus parasuis by Inserting Tn5 Transposon and the Screening of Attenuated Strain

[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.False positive was identified by PCR and then removed.Mice were infected to detect the virulence of mutants.The bionomics of attenuated strains were detected,too.[Result] The attenuated mutants showed similar reproductive activity to that of wild strain.The virulence of mutants was still stable after 30 passages.[Conclusion] This study provided foundation for exploring the virulence factors and pathogenic mechanism of HPS.

UV-C照射对鲜切豇豆的保鲜效果研究

为探究短波紫外线(UV-C)照射对鲜切豇豆的保鲜效果,在预试验结果的基础上,分别采用0、0.5 kJ/m^(2)的UV-C处理豇豆,然后将其置于4℃条件下贮藏,定期测定相关指标。结果表明:采用0.5 kJ/m^(2)UV-C照射可以维持鲜切豇豆较高的VC、可溶性固形物、可溶性蛋白和叶绿素含量,减少鲜切豇豆丙二醛(MDA)的积累,同时还能保持鲜切豇豆较高的总酚、类黄酮含量,并提高抗氧化酶的活性,包括过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX),一定程度上稳定多酚氧化酶(PPO)的活性。综合来说,0.5 kJ/m^(2)UV-C处理可用于鲜切豇豆的贮藏保鲜。

装饰用UV延迟固化环保型胶粘剂制备及性能分析

针对传统热固化技术中效率低、材料强度低等问题,制备一种UV延迟固化胶粘剂,并对其工艺进行优化,研究其强度、热稳定性、耐化学性等。试验结果表明,选择25%EP3作为活性稀释剂,1%TR-PAG-20101作为阳离子光引发剂,光固化时间为10 s;试验制备的25%EP3UV延迟固化胶粘剂的粘接强度为(3.52±0.16)MPa,拉伸剪切强度为3.6 MPa,固化反应时间在5 min之内,热分解温度在300℃以上;材料在沸水和酸性溶液(pH=2)环境下,强度依然较好,其中,酸性溶液浸泡后强度为(3.36±0.40)MPa。因此,试验制备的UV延迟固化胶粘剂具备良好的力学性能。

超声耦合TiO_(2)/UV光催化处理对玉米秸秆组分影响研究

本文采用超声耦合Ti O_(2)/UV光催化处理玉米秸秆,探究处理条件对玉米秸秆组分及结构的影响。研究结果表明,在Ti O_(2)投加量为0.25g·L^(-1)、pH值为8.25、超声强度为0.625W·m L^(-1)、处理1h的条件下,玉米秸秆中木质素和半纤维素含量分别由未处理前的26.06%、20.58%降低到22.85%、18.39%,纤维素含量由37.67%增加到40.39%。超声耦合Ti O_(2)/UV光催化处理可以破坏玉米秸秆的结构,玉米秸秆断裂破碎成细小碎片,表面粗糙有褶皱。本研究可为超声耦合Ti O_(2)/UV光催化技术在玉米秸秆预处理中的应用提供技术参考。

UV平板打印技术在核电DCS成套中的研究与应用

随着核电技术的快速发展,核电DCS成套设备对标识、标记等工艺要求不断提高,传统的标识方法已难以满足高精度、高效率的需求。本文深入研究了UV平板打印技术,探讨了其在核电DCS成套设备中的应用,并对其优势进行了详细分析。实验结果表明,UV平板打印技术能够显著提高标识的清晰度和效率,为核电DCS成套设备的制造和维护提供了有力的技术支持。

UV-B照射时长对酿酒葡萄果实品质及类黄酮代谢产物的影响

为探明UV-B照射时长对赤霞珠酿酒葡萄果实品质及类黄酮物质的影响,试验设立UV-B每天分别照射2、4、6、8 h共4个梯度,以不进行UV-B照射为对照(CK),对不同UV-B照射时长葡萄果实品质及类黄酮物质进行检测分析。结果表明,短时间的UV-B照射会增加果实中可溶性糖含量,UV-B不同照射时长处理的总酚、单宁、总类黄酮、黄烷-3-醇和总花色苷含量均增加;UV-B不同照射时长对酿酒葡萄果皮中的类黄酮代谢产物影响显著,筛选出差异代谢物13个,其中5种物质显著上调、8种物质显著下调;在类黄酮和次生代谢产物合成通路上分别富集了7个差异代谢物,占代谢物总数的77.78%。利用主成分对果实品质和果皮类黄酮产物测定值进行综合评价,得分从高到低依次为UV-B照射2 h>UV-B照射8 h>UV-B照射4 h>UV-B照射6 h>CK。UV-B照射酿酒葡萄赤霞珠2 h时,果实品质和类黄酮代谢产物表现最佳。

Immune Responses to the Attenuated Mycoplasma hyopneumoniae 168 Strain Vaccine by Intrapulmonic Immunization in Piglets

To investigate the immune responses to the attenuated Mycoplasma hyopneumoniae 168 strain vaccine, 8-15 d old piglets were immunized with M. hyopneurnoniae 168 strain vaccine by intrapulmonic route. And the specific IgG antibody in serum, lymphoproliferation, IFNT, and specific secretory IgA （SIgA） antibody in bronchoalveolar lavage fluid were detected on 30 and 60 d post-immunization （DPI）, respectively. On 60 DPI, all the pigs except for those in health control group were challenged with a field M. hyopneumoniae strain JS. Necropsy was performed on 30 d post-challenge （DPC）. The results showed that IFN7 and specific SIgA were stimulated on surface of respiratory tract after immunization. And peripheral blood mononuclear cells could also be proliferated about 1.81 and 2.12 fold on 30 and 60 DPI when stimulated by M. hyopneumoniae protein in vitro. However, no serum IgG antibody against M. hyopneumoniae was detected during the whole immune phage. After challenge, vaccinated pigs were observed with only very slight histological lesion in individual lobes. None of vaccinated pigs showed any clinical signs. While the unvaccinated pigs from challenge control group showed varying degrees of clinical sign and severe macroscopical lesion of mycoplasmal pneumonia of swine （MPS）. The result suggested that the attenuated M. hyopneumoniae 168 strain vaccine inoculated by intrapulmonic route could activate the systemic cellular immunity, the local mucosal immunity and IFNγ secretion in respiratory tract to against M. hyopneumoniae infection in piglets.

Oral Immunization of Mice With Vaccine of Attenuated Salmonella typhimurium Expressing Helicobacter pylori Urease B Subunit

Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori （H. pylori） B subunit （UreB） and to determine whether it could be used as an oral vaccine against H. pylori infection. Methods Using genomic DNA of H. pylori Sydney strain （SS1） as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LBS000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups （including body weight, gastric inflammation, etc.） were also collected. Results The sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H, pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-T and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed. Conclusion The attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection.

RECONSTRUCTION OF THE ATTENUATED RADON TRANSFORM IN π-SCHEME SHORT-SCAN SPECT

In this work, the image reconstruction in π-scheme short-scan single-photon emission computed tomography （SPECT） with nonuniform attenuation is derived in its most general form when π-scheme short-scan SPECT entails data acquisition over disjoint angular intervals without conjugate views totaling to π radians. The reconstruction results are based on decomposition of Novikov＇s inversion operator into three parts bounded in the L2 sense. The first part involves the measured partial data; the second part is a skew-symmetric operator; the third part is a symmetric and compact contribution. It is showed firstly that the operators involved belong to L（L^2（B）. Furthermore numerical simulations are conducted to demonstrate the effectiveness of the developed method.

H2 strain attenuated live hepatitis A vaccines:protective efficacy in a hepatitis A outbreak

AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (10(6.5) TCID(50)) of H2 strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997.Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.RESULTS:HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 days. Overall 302 HA cases were found, 192(63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95% CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1(0.40%) overt and 11(4.06%) asymptomatic HAV cases were found in 271 vaccinees but 21(6.69%) of overt and asymptomatic ones were found in 314 controls.CONCLUSION:H2 strain vaccines were excellent in preventing overt hepatitis A,but not so effective in preventing asymptomatic hepatitis A virus infection.A booster dose might be needed to get permanent reliable immunity.

HPLC-UV法同时测定赤血康脉胶囊中五种成分

本研究旨在建立HPLC-UV法同时测定赤血康脉胶囊中芍药苷、毛蕊异黄酮葡萄糖苷、β-蜕皮甾酮、阿魏酸和党参炔苷的含量。采用DiamonsilR C_(18)(250 mm×4.6 mm,5μm)色谱柱;流动相为乙腈-0.1%磷酸(梯度洗脱);流速为1.0 mL/min;柱温为35℃;检测波长为268 nm,进行分析。结果显示,5种化学成分在各自范围内线性关系良好(r>0.9995);精密度、稳定性、重复性试验结果的RSD均小于2.0%,平均加样回收率99.35%~101.59%,RSD 0.95%~2.69%。该含量测定方法简单可靠、重复性好,操作便捷,适用于同时测定赤血康脉胶囊中五种成分的含量。

Induction of deletion mutation on ompR gene of Salmonella enterica serovar Typhi isolates from asymptomatic typhoid carriers to evolve attenuated strains for vaccine development

Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Mamakkal,Tamil Nadu.India.Both strains were grown in LB(Luria Bertani) medium supplemented with various concentration of NaCl(0.1- 0.7M) respectively.The effecl of osmolar stress was determined at molecular level by PCR using MCR 06 and MCR07 primers corresponding to ompR with chromosomal DNA of S.typhi SS3 and SS5 strains.Attenuation by osmolar stress results in deletion mutation of the.S.typhi slrains was determined by agglutination assays,precipitation method.SDS PAGE analysis and by animal models.Results:The 799 bp amplified ompR gene product from wild type S.typhi SS3 and SS5 illustrate the presence of virulent gene.Interestingly,there was only a 282 bp amplified product from S.typhi SS3 and SS5 grown in the presence of 0.5.0.6 and 0.7 M NaCl.This illustrates the occurrence of deletion mutation in ompR gene al high concentration of NaCl.Furthermore,both the wildtype and mutant S.typhi outer membrane SDS-PAGF.profile reveals the differences in the expression of ompF.ompC and ompA proteins.In mice,wild type and mutant strains lethal dose(LD_(50)) were determined.The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU-mL^(-1).When the mice were injected with the mutants in same dosage,no clinical symptoms were observed;whereas the serum antibodv litre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response.These results suggest that S.typhi SS3 and SS5 may bo used as good candidate strains for the development of live attenuated vaccine against salmonellosis.Conclusions:This study demonstrates that the S.typhi strains were allenualed and could be good vaccine candidates in future.

UV接枝聚硅氧烷-TiO_(2)复合棉织物的制备及性能

通过紫外辐射3-(异丁烯酰氧)丙基三甲氧基硅烷对棉织物进行接枝聚合改性,然后与钛酸四丁酯共水解,形成Si—O—Ti化学键,通过化学键合的形式引入TiO_(2)层。由于Si元素位于棉织物和二氧化钛之间,阻断TiO_(2)光催化降解棉织物。化学键合TiO_(2)与棉织物的结合强度高,提高了耐久性。TiO_(2)对棉织物的整体结构未造成改变,但棉织物的抗紫外线能力显著提升,禁带宽度变小,光催化自清洁能力增强。