儿科病房抗生素相关性腹泻的临床观察

目的观察儿科病房抗生素相关性腹泻(antibiotic associated diarrhea,AAD)的临床表现。方法对983例使用抗生素的患儿进行分析,根据是否发生AAD分为两组,AAD组共有76例患儿,未发生AAD的对照组有907例患儿。分析AAD组患儿使用抗生素的情况,并对两组患儿的基本情况进行比较分析。结果对AAD患儿抗生素使用种类进行分析,发现导致AAD的抗生素主要有三类,其中美洛西林/舒巴坦使用率最高,为18.4%,其次为美洛西林、头孢哌酮/舒巴坦和阿奇霉素,均为14.5%。并且,AAD的发生与性别无关(P0.05)。但是AAD在体重较轻、低龄、抗生素使用时间较长和抗生素联用患儿中多发(P0.05)。这些因素均会导致患儿住院时间延长并出现重要器官损伤现象。结论儿科病房中抗生素的使用要合理科学,尽量减少AAD的发生。     

Poplar and shrub willow energy crops in the United States: field trial results from the multiyear regional feedstock partnership and yield potential maps based on the PRISM‐ELM model

To increase the understanding of poplar and willow perennial woody crops and facilitate their deployment for the production of biofuels, bioproducts, and bioenergy, there is a need for broadscale yield maps. For national analysis of woody and herbaceous crops production potential, biomass feedstock yield maps should be developed using a common framework. This study developed willow and poplar potential yield maps by combining data from a network of willow and poplar field trials and the modeling power of PRISM‐ELM. Yields of the top three willow cultivars across 17 sites ranged from 3.60 to 14.6 Mg ha^?1 yr^?1 dry weight, while the yields from 17 poplar trials ranged from 7.5 to 15.2 Mg ha^?1 yr^?1. Relationships between the environmental suitability estimates from the PRISM‐ELM model and results from field trials had an R² of 0.60 for poplar and 0.81 for willow. The resulting potential yield maps reflected the range of poplar and willow yields that have been reported in the literature. Poplar covered a larger geographic range than willow, which likely reflects the poplar breeding efforts that have occurred for many more decades using genotypes from a broader range of environments than willow. While the field trial data sets used to develop these models represent the most complete information at the time, there is a need to expand and improve the model by monitoring trials over multiple cutting cycles and across a broader range of environmental gradients. Despite some limitations, the results of these models represent a dramatic improvement in projections of potential yield of poplar and willow crops across the United States.     

The status of marine fish larval-rearing technology in Australia

Over 20 marine fish species have been studied forfarming or stock enhancement in Australia. However,commercial production has been dominated by the cageculture of Salmo salar in Tasmania, Thunnusmaccoyiiin South Australia, and to a lesser extent Latescalcarifer in Queensland. A major impediment to thecommercial production of new species has been thelarge-scale production of juvenile fish. Thedevelopment of marine fish larval rearing technologyin Australia has had four main influences over thelast decade: culture system technology from France,live food culture and nutritional enhancement fromBelgium, artificial diets from Japan and extensivepond culture from the USA. Microalgae and live foodculture is based on traditional aquaculture speciesand methods. Recent Australian research has focusedon induced spawning, the role of stress in inhibitingovulation, factors influencing initial swim bladderinflation in larvae, larval nutrition, extensiveculture and diagnosis of disease. Over the next 5years, Australian aquaculturists should be able toproduce industrial quantities of a range of nativemarine fish, either in intensive fish hatcheries, orin combination with extensive pond culture.     

骨髓移植后的白血病患者环境微生物控制与感染关系研究

白血病患者骨髓移植后,易引起各类微生物感染而死亡。通过F_1鼠9Gy^(60)Co照射(最大致死量)骨髓移植后,行环境微生物控制,将其数据结合临床特点,设计的白血病患儿骨髓移植,环境微生物监控的层流病房。自1989～1993年12例患儿行骨髓移植无一例感染。     

集约经营对毛竹林土壤碳氮库及酶活性的影响

为探明集约经营对毛竹林土壤碳库、氮库以及酶活性的影响,在浙江省临安市选取相邻的粗放经营毛竹林和集约经营毛竹林(经营年限为15年),测定表层(0～20 cm)与亚表层(20～40 cm)土壤不同形态碳氮和蔗糖酶、脲酶、过氧化氢酶和酸性磷酸酶的活性.结果表明: 长期集约经营显著降低毛竹林土壤有机碳含量和储量,表层和亚表层土壤有机碳储量分别下降13.2%和18.0%;集约经营15年后,毛竹林表层和亚表层土壤水溶性碳、热水溶性碳、微生物生物量碳和易氧化碳含量均显著降低;与粗放经营毛竹林相比,集约经营毛竹林表层和亚表层土壤氮储量分别增加50.8%和36.6%;集约经营显著增加毛竹林土壤硝态氮和铵态氮含量,显著降低土壤水溶性氮和微生物生物量氮含量;集约经营15年后,毛竹林表层土壤蔗糖酶、脲酶、过氧化氢酶和酸性磷酸酶活性均显著下降,亚表层土壤酸性磷酸酶活性显著下降,而其他酶活性均无显著变化.长期集约经营导致毛竹林土壤碳储量、活性碳库和微生物活性显著下降,在以后的经营过程中要注意化肥与有机肥配合使用,以保证毛竹林的可持续经营.     

Social jetlag affects subjective daytime sleepiness in school-aged children and adolescents: A study using the Japanese version of the Pediatric Daytime Sleepiness Scale (PDSS-J)

The aim of this study was to elucidate the level of daytime sleepiness in Japanese school-aged children and adolescents, and to examine associated factors including sleep loss and social jetlag using the Japanese version of the Pediatric Daytime Sleepiness Scale (PDSS-J). After the linguistic validation of the PDSS-J with a multi-step translation methodology, consisting of forward translation, back translation, expert review and cognitive debriefing interviews, we conducted a psychometric validation for 492 students aged 11–16 years (46.7% boys) of public elementary school, junior high school and high school, using the PDSS-J, the Karolinska Sleepiness Scale (KSS), and bedtimes and wake-up times on school days and free days. Internal consistency (Cronbach’s alpha) of the PDSS-J was 0.77, and the test–retest reliability demonstrated by the intraclass coefficient was 0.88. Multivariate logistic regression analysis revealed that both short sleep duration and social jetlag were identified as factors associated with daytime sleepiness, after adjustment for age and sex. PDSS-J scores were significantly higher in the group with large social jetlag with or without sufficient sleep duration than in the group with sufficient sleep duration and small social jetlag. The PDSS-J is an important tool for assessing daytime sleepiness, given its ease of administration and robust psychometric properties. The impact of not only sleep loss but also social jetlag on daytime sleepiness among school-aged children and adolescents must be fully taken into account.     

Enhanced purification of Mullerian inhibiting substance by lectin affinity chromatography

Mullerian inhibiting substance (MIS), a secreted testicular product responsible for regression of the Mullerian ducts in the male mammalian embryo, was purified 7000 fold, exploiting the glycoprotein nature of this important fetal regressor to achieve enhanced purification. The present procedure employs media incubation of newborn calf testis, passage through DEAE Bio-Gel A and CM Bio-Gel A and sequential lectin affinity chromatography on wheat germ lectin (WGL)-Sepharose 6MB and concanavalin A (Con A)-Sepharose 4B. Strongly bioactive MIS was released from both lectin columns in the bound glycoprotein fraction only after elution with lectin-specific sugar. Carbohydrate analysis of the highly purified glycoprotein fraction eluted from Con A indicated the presence of both N-acetyl glucosamine and mannose, as would be expected from its sequential lectin affinity, as well as of galactose, galactosamine and N-acetyl neuraminic acid. Electrophoresis of this fraction on polyacrylamide-SDS gels showed an identical band pattern after staining with either Coomassie blue or periodic acid-Schiff reagent, further indicating that MIS is a glycoprotein.     

Macroscopic anisotropic bone material properties in children with severe osteogenesis imperfecta

Children with severe osteogenesis imperfecta (OI) typically experience numerous fractures and progressive skeletal deformities over their lifetime. Recent studies proposed finite element models to assess fracture risk and guide clinicians in determining appropriate intervention in children with OI, but lack of appropriate material property inputs remains a challenge. This study aimed to characterize macroscopic anisotropic cortical bone material properties and investigate relationships with bone density measures in children with severe OI. Specimens were obtained from tibial or femoral shafts of nine children with severe OI and five controls. The specimens were cut into beams, characterized in bending, and imaged by synchrotron radiation X-ray micro-computed tomography. Longitudinal modulus of elasticity, yield strength, and bending strength were 32–65% lower in the OI group (p < 0.001). Yield strain did not differ between groups (p ≥ 0.197). In both groups, modulus and strength were lower in the transverse direction (p ≤ 0.009), but anisotropy was less pronounced in the OI group. Intracortical vascular porosity was almost six times higher in the OI group (p < 0.001), but no differences were observed in osteocyte lacunar porosity between the groups (p = 0.086). Volumetric bone mineral density was lower in the OI group (p < 0.001), but volumetric tissue mineral density was not (p = 0.770). Longitudinal OI bone modulus and strength were correlated with volumetric bone mineral density (p ≤ 0.024) but not volumetric tissue mineral density (p ≥ 0.099). Results indicate that cortical bone in children with severe OI yields at the same strain as normal bone, and that their decreased bone material strength is associated with reduced volumetric bone mineral density. These results will enable the advancement of fracture risk assessment capability in children with severe OI.     

Influence d'une alimentation préalable et du jeûne sur l'apparition de la recherche intensive des proies chez Semiadalia undecimnotata

Résumé Les prédateurs qui vivent aux dépens de ressources alimentaires groupées, modifient leur mode de déplacement après la capture et l'ingestion d'une proie. Ils passent de la recherche extensive (déplacements rapides et linéaires) à la recherche intensive (déplacements lents et sinueux). Chez les adultes et les larves de dernier stade de la coccinelle Semiadalia undecimnotata Schn. (Col., Coccinellidae), dans les premières heures qui suivent leur naissance ou leur mue, l'ingestion d'un premier puceron ne modifie pas les caractéristiques locomotrices individuelles: les déplacements restent de type extensif. Au début de chaque stade, cette coccinelle présente une période de sensibilisation à la proie rencontrée. Durant ces laps de temps, elle doit consommer plusieurs proies avant d'être capable d'adopter la recherche intensive. L'existence d'une période de jeûne avant cette première prise alimentaire favorise, au contraire, l'adoption de la recherche intensive.

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The ladybird, Semiadalia undecimnotata, like all other entomophagous insects feeding on relatively sedentary prey, exhibits two types of walking pattern during the search for prey: xtensive and intensive search. The latter is engaged following detection of visual or chemical cues. Changes in the ladybird search pattern: extensive search—a single prey capture—intensive search, were investigated in relation to experience of prior feeding-periods (experienced coccinellids) or to lack of such experience (naïve coccinellids) and with respect to changes in duration of fasting. The analysis of their pathways was performed initially by comparison of three locomotory paramètres: the number of stops (number/s), the walking speed (mm/s) and the turning-rate (degrees/s), and subsequently by statistical classification (principle components analysis). Unlike experienced coccinellids, observations of naïve coccinellids, indicate that a single feeding session during the three to five hours after emergence of an adult, or ecdysis of the larva, will change the walking pattern slightly. These animals will maintain extensive search or adopt a particular, intermediate locomotory pattern which is a development of extensive search but do not adopt intensive search. Fasting, for periods over twelve hours, favoured intensive search in populations studied. It is probable that the requirement to feed on more than one prey item before adopting intensive search involves concepts such as forms of learning (sensitization).

     

Clinical and immunological features of convalescent pediatric patients infected with the SARS-CoV-2 Omicron variant in Tianjin,China

COVID-19 has spread surprisingly fast worldwide, and new variants continue to emerge. Recently, the World Health Organization acknowledged a new mutant strain “Omicron”, with children were accounting for a growing share of COVID-19 cases compared with other mutant strains. However, the clinical and immunological characteristics of convalescent pediatric patients after Omicron infection were lacking. In this study, we comparatively analyzed the clinical data from pediatric patients with adult patients or healthy children and the effects of SARSCoV-2 vaccine on the clinical and immune characteristics in convalescent pediatric patients. Our results indicated that convalescent pediatric patients had unique clinical and immune characteristics different from those of adult patients or healthy children, and SARS-CoV-2 vaccination significantly affected on the clinical and immune characteristics and the prevention of nucleic acid re-detectable positive (RP) in convalescent patients. Our study further deepens the understanding of the impact of Omicron on the long-term health of pediatric patients and provides a valuable reference for the prevention and treatment of children infected with Omicron.