Abstract Plasma nitriding is a plasma-activated thermochemical method widely used to increase the fatigue strength, hardness and wear resistance of low-alloy steels. In this work, a new structure consisting of a hollow cathode metal plate can produce a hollow cathode discharge and heat the workpiece by radiation. This principle is used to perform hollow cathode source plasma nitriding (HCSPN). Herein, 42CrMo steels were treated by conventional plasma nitriding (CPN) and HCSPN treatments. The 42CrMo steels were nitrided at 525 °C for 6 h in NH3 atmosphere. The mechanical and dry wear properties were measured by nano-indentation, Vickers micro-indentation and ball-on-disk tribometer, respectively. The H3/E⁎2 ratio was 0.0274 GPa (H=11.51 GPa and E⁎=235.84 GPa) for the CPN sample and 0.0276 GPa (H=10.87 GPa and E⁎=215.54 GPa) for the HCSPN sample. Compared with the untreated 42CrMn steel, all the nitrided samples possess increased fracture toughness. Because the workpiece was not used as a discharge cathode, this HCSPN treatment overcame the disadvantages of the conventional CPN treatment. Additionally, results showed that the surface of the HCSPN sample was smoother than that of the CPN sample, and its tribological performance was better.

RESUMO: A milhã é uma das piores plantas daninhas exóticad em regiões tropicais, subtropicais e temperadas do mundo. Neste estudo, os fatores abióticos que afetam a germinação e a emergência inicial da plântula de milhã foram investigados em laboratório. As melhores temperaturas de germinação foram observadas entre 25 e 35 oC sob o regime de 12 horas de luz/12 horas de escuridão. Algumas sementes conseguem germinar no escuro, mas a exposição à luz estimulou a germinação consideravelmente. A semente de milhã apresentou tolerância à salinidade (entre 0 a 160) e baixo potencial hídrico (11% de germinação a -0,8 MPa). Não foi observado efeito significativo do pH médio sobre a germinação das sementes e mais de 90% da germinação das sementes ocorreu ao longo de uma grande faixa de variação de pH (entre 4,0 e 10,0). A germinação das sementes foi bastante influenciada pelo choque térmico, sendo completamente inibida a 140 oC durante 5 min. A maior taxa de emergência das plântulas foi de 96%, com as sementes que haviam sido plantadas a uma profundidade do solo de 1 cm. O conhecimento gerado a respeito da biologia de germinação neste estudo será útil no desenvolvimento de estratégias de manejo integrado para esta espécie, e também no combate ao estabelecimento da milhã como uma planta daninha problemática em regiões de cultivo economicamente importantes.

ABSTRACT: Large crabgrass is one of the worst exotic weed in tropical, subtropical, and temperate regions of the world. In this study, the abiotic factors affecting seed germination and early seedling emergence of large crabgrass were investigated under laboratory conditions. The optimum temperatures of germination occurred at the range from 25 to 35 oC under 12 h light/12 h dark condition. Some seeds could germinate in the dark, but light exposure significantly stimulated the germination. Large crabgrass seed was tolerant to salinity level range of 0 to 160 and low water potential (11% germination at -0.8 MPa). Medium pH had no significant effect on seed germination and more than 90% seeds germination was obtained over a broad pH range from 4.0 to 10.0. Seed germination was significantly influenced by heat-shock and completely inhibited at 140 oC for 5 min. The greatest seedling emergence rate was 96% when seeds were planted at a soil depth of 1 cm. Knowledge of germination biology obtained from this study will be useful in the development of the integrated weed management strategies for this species, and to avoid its establishment as a troublesome weed in economically important cropping regions.

Bone morphogenetic protein 2 (BMP2) and basic fibroblast growth factor (bFGF) have been shown to exhibit a synergistic effect to promote bone repair and healing. In this study, we constructed a novel adenovirus with high coexpression of BMP2 and bFGF and evaluated its effect on osteogenic differentiation of goat bone marrow progenitor cells (BMPCs). Recombinant adenovirus Ad-BMP2-bFGF was constructed by using the T2A sequence. BMPCs were isolated from goats by density gradient centrifugation and adherent cell culture, and were then infected with Ad-BMP2-bFGF or Ad-BMP2. Expression of BMP2 and bFGF was detected by ELISA, and alkaline phosphatase (ALP) activity was detected by an ALP assay kit. In addition, von Kossa staining and immunocytochemical staining of collagen II were performed on BMPCs 21 days after infection. There was a high coexpression of BMP2 and bFGF in BMPCs infected with Ad-BMP2-bFGF. Twenty-one days after infection, ALP activity was significantly higher in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. Larger and more mineralized calcium nodules, as well as stronger collagen II staining, were observed in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. In summary, we developed a novel adenovirus vector Ad-BMP2-bFGF for simultaneous high coexpression of BMP2 and bFGF, which could induce BMPCs to differentiate efficiently into osteoblasts.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that affects the striatum most severely. However, except for juvenile forms, relative preservation of the cerebellum has been reported. The objective of the present study was to perform MRI measurements of caudate, putamen, cerebral, and cerebellar volumes and correlate these findings with the length of the CAG repeat and clinical parameters. We evaluated 50 consecutive patients with HD using MRI volumetric measurements and compared them to normal controls. Age at onset of the disease ranged from 4 to 73 years (mean: 43.1 years). The length of the CAG repeat ranged from 40 to 69 (mean: 47.2 CAG). HD patients presented marked atrophy of the caudate and putamen, as well as reduced cerebellar and cerebral volumes. There was a significant correlation between age at onset of HD and length of the CAG repeat, as well as clinical disability and age at onset. The degree of basal ganglia atrophy correlated with the length of the CAG repeat. There was no correlation between cerebellar or cerebral volume and length of the CAG repeat. However, there was a tendency to a positive correlation between duration of disease and cerebellar atrophy. While there was a negative correlation of length of the CAG repeat with age at disease onset and with striatal degeneration, its influence on extrastriatal atrophy, including the cerebellum, was not clear. Extrastriatal atrophy occurs later in HD and may be related to disease duration.

OBJECTIVE: To test the efficacy of locally produced Vi vaccine over a time period of longer than one year. METHODS: A double-blinded, randomized field trial was performed in Guangxi Zhuang Autonomous Region in south-western China, using 30 mg doses of locally produced Vi. Enrolled subjects were 3-50 years of age, although the majority (92%) were school-aged children, who have the highest rate of typhoid fever in this setting. A total of 131 271 people were systematically allocated a single dose of 30 mg of Vi polysaccharide or saline placebo. The study population was followed for 19 months, with passive surveillance conducted in the Ministry of Health and the Regional Health and Anti-epidemic Centre (HAEC). Clinically suspected cases of typhoid fever were confirmed by blood culture, or by serological reaction with O-antigen (Widal tests). FINDINGS: After 19 months, there were 23 culture-confirmed cases of typhoid fever in the placebo group versus 7 cases in the Vi group (Protective efficacy (PE) = 69%; 95% CI = 28%, 87%). Most of the isolates were from school-aged children: 22 cases in the placebo group versus 6 in the Vi group (PE = 72%; 95% CI = 32%, 82%). No serious post-injection reactions were observed. The locally produced Vi polysaccharide vaccine showed levels of protective efficacy similar to those for Vi vaccine produced in industrial countries. CONCLUSION: The slightly higher dose of vaccine did not seem to alter efficacy significantly in China.

OBJETIVO: Determinar la eficacia de la vacuna de Vi producida localmente a lo largo de un periodo superior a un año. MÉTODOS: Se llevó a cabo un ensayo sobre el terreno aleatorizado y en doble ciego en la región autónoma (provincia) de Guangxi Zhuang, en el suroeste de China, usando dosis de 30 mg de la vacuna Vi producida localmente. El intervalo de edades de las personas participantes era de 3-50 años, si bien la mayoría de ellas (92%) eran niños en edad escolar, los más afectados por la fiebre tifoidea en ese lugar. Se asignó de forma sistemática a un total de 131 271 personas para que recibieran ya fuera una dosis única de 30 mg de polisacárido Vi o bien un placebo constituido por suero fisiológico. La población estudiada fue objeto de seguimiento durante 19 meses, y la vigilancia pasiva corrió a cargo del Ministerio de Salud y del Centro Regional de Salud y Lucha contra las Epidemias (HAEC). Los casos con manifestaciones clínicas sugestivas de fiebre tifoidea fueron confirmados mediante cultivo sanguíneo o mediante la reacción serológica con el antígeno O (pruebas de Widal). RESULTADOS: Al cabo de 19 meses se habían confirmado mediante cultivo 23 casos de fiebre tifoidea en el grupo placebo, frente a 7 casos en el grupo tratado con la vacuna Vi (eficacia protectora (EP) = 69%; IC95% = 28-87%). La mayoría de los aislados correspondían a niños en edad escolar: 22 casos en el grupo placebo, frente a 6 en el grupo tratado con Vi (EP = 72%; IC95% = 32-82%). No se observó ninguna reacción grave postinyección. La vacuna basada en el polisacárido Vi producida localmente demostró tener una eficacia protectora similar a la de la vacuna Vi producida en los países industrializados. CONCLUSIÓN: El ligero aumento de la dosis de vacuna no parece haber influido de forma significativa en su eficacia en China.

OBJECTIF:Tester l’efficacité du vaccin antityphoïdique polyosidique Vi de production locale sur une période de plus d’un an. MÉTHODS: Un essai de terrain randomisé en double aveugle a été réalisé dans la région autonome (province) de Guanxi Zhuang dans le sud-ouest de la Chine, au moyen de doses de 30 mg de polyoside Vi de production locale. Les sujets recrutés dans l’étude étaient âgés de 3 à 50 ans, mais étaient pour la plupart (92 %) des enfants d’âge scolaire, groupe qui présente le taux le plus élevé de fièvre typhoïde dans cette région. Au total, 131 271 personnes ont reçu systématiquement une dose unique de 30 mg de polyoside Vi ou un placebo (soluté physiologique). La population d’étude a été suivie pendant 19 mois dans le cadre d’une surveillance passive exercée par le Ministère de la Santé et le Centre régional de la santé et de la lutte contre les épidémies (HAEC). Les suspicions cliniques de fièvre typhoïde ont été confirmées par hémoculture ou par réaction sérologique en présence d’antigène O (test de Widal). RÉSULTATS: Au bout de 19 mois, on a dénombré 23 cas de fièvre typhoïde confirmés par culture dans le groupe placebo contre 7 cas dans le groupe Vi (efficacité protectrice (EP) = 69% ; intervalle de confiance à 95% (IC 95 %) : 28-87 %). La plupart des isolements ont été réalisés chez les enfants d’âge scolaire, avec 22 cas dans le groupe placebo contre 6 cas dans le groupe Vi (EP = 72%; IC 95%: 32-82 %). Aucune réaction grave n’a été observée après l’injection. Le vaccin polyosidique Vi de production locale a montré des taux d’efficacité protectrice similaires à ceux des vaccins produits dans les pays industrialisés. CONCLUSION: La dose légèrement plus forte de vaccin n’a pas semblé modifier l’efficacité de fac¸on significative en Chine.