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161.
目的:探讨开放性楔形胫骨高位截骨术(OWHTO)中采用不同目标力线对单间室膝关节骨性关节炎(KOA)疗效的影响。方法:回顾性分析本院收治的2016年9月~2018年9月采用OWHTO治疗单间室KOA患者41例的临床资料,根据不同目标力线分为固定力线组和个体化力线组,固定力线组19例患者采用统一调目标力线至Fujisawa点治疗,个体化力线组22例根据术中关节软骨Outerbridge分级、个体化调定目标力线治疗,对比两组术前及术后1.5个月、3个月、6个月、12个月的疼痛视觉模拟评分(VAS)及美国特种外科医院膝关节(HSS)评分变化,并对比术前和12个月时MRI及关节镜影像。结果:术后所有患者VAS评分、HSS评分均较术前改善(P0.05),其中个体化力线组术后1.5个月、3个月时VAS评分优于固定力线组,差异有统计学意义(P0.05)。MRI及关节镜显示两组患者均有不同程度软骨再生。结论:采用OWHTO治疗单间室KOA,根据患者不同软骨磨损情况制定个体化目标力线方案有利于患者早期疼痛的改善,但其长期功能的恢复及软骨再生与固定力线方案无明显差异。 相似文献
162.
《Animal : an international journal of animal bioscience》2020,14(1):161-170
Weaning of beef calves is a stressful event that negatively impacts health and performance. A variety of interventions have been proposed to reduce stress and improve gains following weaning. This study used 288 7- to 8-month-old calves from two separate locations, to examine four different weaning strategies, as well as the impact of shipment. Calves were blocked by weight and sex, and then randomly assigned to one of four treatments: abrupt weaning (AW), where calves were separated from the dam on day 0 (D0) and allowed no further contact with the dam; fence line (FL), where calves were weaned on D0 but had fence line contact with dams for 7 days; nose flap (NF), where on day -6 calves received a nose flap that interferes with suckling, then had the flap removed and were weaned from the dam on D0; and intermittent separation (SEP), where calves were removed from dams for 24-h intervals on day -13 and day -6, then weaned on D0, but allowed fence line contact with the dam for 7 days. Each treatment group was further divided into two subgroups, one of which was shipped early (D0 for AW, day 7 for others) or shipped later (day 28). Body weight and sickness were recorded for all groups. Results showed a negative impact on gain for early shipping compared to later shipping, and poorer gain in AW calves than most other treatments. Results of the analyses of morbidity were inconclusive. This study found that delayed shipment following FL weaning improves performance under common management conditions for the US cow–calf industry. 相似文献
163.
《Animal : an international journal of animal bioscience》2020,14(4):846-853
The competitiveness and sustainability of low input cost dairy production systems are generally supported by efficient use of pasture in the diets. Therefore, pasture intake directly affects overall efficiency of these systems. We aimed to assess feeding and grazing management main factors that affect pasture dry matter intake (DMI) in commercial dairy farms during the different seasons of the year. Fortnightly visits to 28 commercial dairies were carried out between June 2016 and May 2017 to record production and price, supplement offered and price, pasture access time (PAT), herbage mass (HM) and allowance (HA). Only farms with the most contrasting estimated pasture DMI per cow (eDMI) were compared as systems with high (HPI; N = 8) or low (LPI; N = 8) pasture DMI. Despite a lower individual milk production in HPI than LPI (19.0 v. 23.3 ± 0.7 l/cow, P < 0.01), daily margin over feeding cost was not different between groups (3.07 v. 2.93 ± 0.15 U$S/cow for HPI and LPI, respectively). During autumn and winter, HPI cows ingested more pasture than LPI cows (8.3 v. 4.6 and 5.9 v. 2.9 ± 0.55 kg DM/cow per day, respectively, P < 0.01) although PAT, HM and HA were similar between groups. Both groups offered high supplementation levels during these seasons, even though greater in LPI than HPI (14.7 v. 9.7 ± 0.7 kg DM supplement/cow per day, respectively, P < 0.01). On the other hand, differences between groups for both pasture and supplement DMI were more contrasting during spring and summer (13.1 v. 7.3 ± 0.5 and 4.0 v. 11.4 ± 0.4 kg DM/cow per day for HPI and LPI, respectively, P < 0.01), with higher PAT in both seasons (P < 0.05) and higher HA during summer in HPI than LPI (P < 0.01). Unlike LPI, during these seasons HPI adjusted offered supplement according to HA, achieving a higher pasture eDMI and making more efficient use of available pastoral resource than LPI. As there was no grazing limiting condition for pasture harvesting in either group, the main factor affecting pasture DMI was a pasture by supplement substitution effect. These results reinforce the importance of an efficient grazing management, and using supplements to nutritionally complement pasture intake rather than as a direct way to increase milk production. 相似文献
164.
Caroline J. Rose Katrin Hammerschmidt Yuriy Pichugin Paul B. Rainey 《Ecology letters》2020,23(9):1380-1390
The evolutionary transition to multicellularity has occurred on numerous occasions, but transitions to complex life forms are rare. Here, using experimental bacterial populations as proxies for nascent multicellular organisms, we manipulate ecological factors shaping the evolution of groups. Groups were propagated under regimes requiring reproduction via a life cycle replete with developmental and dispersal (propagule) phases, but in one treatment lineages never mixed, whereas in a second treatment, cells from different lineages experienced intense competition during the dispersal phase. The latter treatment favoured traits promoting cell growth at the expense of traits underlying group fitness – a finding that is supported by results from a mathematical model. Our results show that the transition to multicellularity benefits from ecological conditions that maintain discreteness not just of the group (soma) phase, but also of the dispersal (germline) phase. 相似文献
165.
Zaiyu Zheng Jinxian Yang Junqing Ge Hongshu Chi Bin Chen Qinmei Fang Hui Gong 《Cell biology international》2020,44(3):808-820
In the present study, a new hepatic tissue‐origin cell line from European eel Anguilla anguilla has been developed and characterized. This cell line designated EL has been maintained in Leibovitz L‐15 supplemented with 10% fetal bovine serum over 72 months, and subcultured more than 90 times. The EL cell line consisted predominantly of fibroblast‐like cells, which could survive over 100 days in vitro, and could grow at 15–32°C. The optimum temperature for growth was 27°C. The chromosome analysis revealed a modal diploid karyotype of 2n = 38. The origin of this cell line was confirmed by the 18S recombinant (r)RNA sequencing. The susceptibility test indicated significant cytopathic effects in the EL cells with regard to the Rana grylio virus and the Herpesvirus anguillae. The viral replication was confirmed by transmission electron microscopy and polymerase chain reaction analysis. Following poly (I:C) exposure, the expression levels of the immune‐related molecules interferon regulatory factor‐7 (irf7) and transforming growth factor‐β (TGF‐β) were downregulated in EL cells, whereas the expression levels of the rf3 and the cytochrome P450 (CYP450) were upregulated. All four genes were significantly upregulated following inflammation by lipopolysaccharide (LPS). These data suggested the application of EL cell line for viral identification, as well as for immunodiagnosis and pharmacological targeting. 相似文献
166.
《Saudi Journal of Biological Sciences》2020,27(5):1302-1309
Background and ObjectivesCissus quadrangularis Linn, is a rich bioresource for folk and traditional medicines from ancient times till date. The present study aimed to investigate the free radical scavenging and anticancer efficacy in vitro of the ethanolic and methanolic extract from the aerial parts of Cissus quadrangularis (L).Material and MethodsIn vitro cell-free antioxidant analyses were performed for the ethanolic extract of Cissus quadrangularis (L). (EECQ) and methanolic extract of Cissus quadrangularis (L). (MECQ) using different free radical scavenging assays includes DPPH, nitric oxide, superoxide, metal chelation, and hydrogen peroxide radical scavenging assays. In vitro leukemic cytotoxic assessment by MTT assay was performed both EECQ and MECQ extract against HL-60 cell lines.ResultsStrong antioxidant effects were recorded in EECQ and MECQ in all the cell-free models. The ethanolic extract exhibited a significant dose-dependent free radical activity in comparison with methanolic extracts. The EECQ and MECQ possess pronounced anticancer efficacy against leukemic cells HL-60 with an IC50 value of 36 μg/mL and 40 μg/mL respectively.ConclusionPresent data indicates the presence of marked antioxidant and anticancer behaviors in the extracts of aerial portions of Cissus quadrangularis (L). extracts. Thus, Cissus quadrangularis (L). poses as a promising safe chemopreventive plant to combat cancer. 相似文献
167.
种群数量是物种的重要生态学基础资料,合适的密度调查方法是数量估算的基础。2016年4-5月,采用广泛应用于鸡形目Galliformes鸟类种群密度调查的样线法和样点法,调查了四川黑竹沟国家级自然保护区3种鸡形目鸟类(白腹锦鸡Chrysolophus amherstiae、红腹角雉Tragopan temminckii和血雉Ithaginis cruentus)的种群密度。样线法和样点法估算的雄体密度分别是:白腹锦鸡1.20只/km^2和(6.31±0.98)只/km^2,红腹角雉5.41只/km^2和(0.39±0.17)只/km^2,血雉3.01只/km^2和(5.97±2.70)只/km^2。除红腹角雉外,样点法估算的白腹锦鸡、血雉种群密度均大于样线法。建议针对不同鸡形目鸟类采用不同的调查方法,并尽量扩大样本数量,从而提高调查结果的准确性。 相似文献
168.
169.
Joe Carver Domingos Ng Michelle Zhou Peggy Ko Dejin Zhan Mandy Yim David Shaw Brad Snedecor Michael W. Laird Steven Lang Amy Shen Zhilan Hu 《Biotechnology progress》2020,36(4):e2967
Historically, therapeutic protein production in Chinese hamster ovary (CHO) cells has been accomplished by random integration (RI) of expression plasmids into the host cell genome. More recently, the development of targeted integration (TI) host cells has allowed for recombination of plasmid DNA into a predetermined genomic locus, eliminating one contributor to clone-to-clone variability. In this study, a TI host capable of simultaneously integrating two plasmids at the same genomic site was used to assess the effect of antibody heavy chain and light chain gene dosage on antibody productivity. Our results showed that increasing antibody gene copy number can increase specific productivity, but with diminishing returns as more antibody genes are added to the same TI locus. Random integration of additional antibody DNA copies in to a targeted integration cell line showed a further increase in specific productivity, suggesting that targeting additional genomic sites for gene integration may be beneficial. Additionally, the position of antibody genes in the two plasmids was observed to have a strong effect on antibody expression level. These findings shed light on vector design to maximize production of conventional antibodies or tune expression for proper assembly of complex or bispecific antibodies in a TI system. 相似文献
170.
Guanhua Deng Linbo Cai Jian Feng Song Duan Ping Zhang Sherman X. Xin 《Bioelectromagnetics》2021,42(1):86-94
Artificial materials that can simultaneously mimic the relative permittivity and conductivity of various human tissues are usually used in medical applications. However, the method of precisely designing these materials with designated values of both relative permittivity and conductivity at 3 T MRI resonance frequency is lacking. In this study, a reliable method is established to determine the compositions of artificial dielectric materials with designated relative permittivity and conductivity at 128 MHz. Sixty dielectric materials were produced using oil, sodium chloride, gelatin, and deionized water as the main raw materials. The dielectric properties of these dielectric materials were measured using the open‐ended coaxial line method at 128 MHz. Nonlinear least‐squares Marquardt–Levenberg algorithm was used to obtain the formula, establishing the relationship between the compositions of the dielectric materials and their dielectric properties at 128 MHz. The dielectric properties of the blood, gall bladder, muscle, skin, lung, and bone at 128 MHz were selected to verify the reliability of the obtained formula. For the obtained formula, the coefficient of determination and the expanded uncertainties with a coverage factor of k = 2 were 0.991% and 4.9% for relative permittivity and 0.992% and 6.4% for conductivity. For the obtained artificial materials measured using the open‐ended coaxial line method, the maximal difference of relative permittivity and conductivity were 1.0 and 0.02 S/m, respectively, with respect to the designated values. In conclusion, the compositions of tissue‐mimicking material can be quickly determined after the establishment of the formulas with the expanded uncertainties of less than 10%. Bioelectromagnetics. 2021;42:86–94. © 2020 Bioelectromagnetics Society. 相似文献