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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Alon Peled Ofer Sarig Guangping Sun Liat Samuelov Chi A. Ma Yuan Zhang Tom Dimaggio Celeste G. Nelson Kelly D. Stone Alexandra F. Freeman Liron Malki Lucia Seminario Vidal Latha M. Chamarthy Valeria Briskin Janan Mohamad Mor Pavlovsky Jolan E. Walter Joshua D. Milner Eli Sprecher 《The Journal of allergy and clinical immunology》2019,143(1):173-181.e10
82.
Carlo M. Pesce Rosanna Colacino 《Virchows Archiv : an international journal of pathology》1987,412(2):151-154
Summary The volume of the adenomatous mucosa (V), the area of the surface epithelium (Ss), the area of the glandular epithelium (Sg), and theSg:Ss ratio were calculated in a series of 14 adenomatous polyps (APs) of a case of multiple polyposis of the colon. The equation of simple allometry was used to study the relative growth of the four series of values.Ss grew isometrically with size;Sg overgrewSs and accounted for most of the increase inV. TheSg:Ss ratio increased withSg andV. 相似文献
83.
Mittal N Zhou Y Ung S Linares C Molloi S Kassab GS 《Annals of biomedical engineering》2005,33(8):1015-1026
A rigorous analysis of blood flow must be based on the branching pattern and vascular geometry of the full vascular circuit
of interest. It is experimentally difficult to reconstruct the entire vascular circuit of any organ because of the enormity
of the vessels. The objective of the present study was to develop a novel method for the reconstruction of the full coronary
vascular tree from partial measurements. Our method includes the use of data on those parts of the tree that are measured
to extrapolate the data on those parts that are missing. Specifically, a two-step approach was employed in the reconstruction
of the entire coronary arterial tree down to the capillary level. Vessels > 40 μm were reconstructed from cast data while
vessels < 40 μm were reconstructed from histological data. The cast data were reconstructed one-bifurcation at a time while
histological data were reconstructed one-sub-tree at a time by “cutting” and “pasting” of data from measured to missing vessels.
The reconstruction algorithm yielded a full arterial tree down to the first capillary bifurcation with 1.9, 2.04 and 1.15
million vessel segments for the right coronary artery (RCA), left anterior descending (LAD) and left circumflex (LCx) trees,
respectively. The node-to-node connectivity along with the diameter and length of every vessel segment was determined. Once
the full tree was reconstructed, we automated the assignment of order numbers, according to the diameter-defined Strahler
system, to every vessel segment in the tree. Consequently, the diameters, lengths, number of vessels, segments-per-element
ratio, connectivity and longitudinal matrices were determined for every order number. The present model establishes a morphological
foundation for future analysis of blood flow in the coronary circulation. 相似文献
84.
Maximum effort flow-static recoil curves were obtained in 5 healthy subjects breathing air, He/O2, and SF6/O2 mixtures. In 4 of them maximum effort flows corresponded to really maximal flows and their curves were transformed into compliance curves for the flow limiting segments of the airway and analyzed from the point of view of a previously presented lung model (Pedersen and Nielsen 1976). The results showed, that viscosity dependent pressure losses from the alveoli to the flow limiting segments were minimal for air and SF6/O2, but not for He/O2. When viscosity dependent pressure losses could be neglected, then expiration of gases of different densities gave almost identical compliance curves for the flow limiting segments. This supported the applicability of the model. The calculated compliance curves for the flow limiting segments were compared with data from the literature, and the findings indicated that flow limitation during expirations with just maximal flows throughout began in the extrapulmonary airways and moved upstream during the expiration. 相似文献
85.
R. G. McMurray T. K. Eubank A. C. Hackney 《European journal of applied physiology》1995,72(1-2):121-126
The effects of resistance exercise on the nocturnal responses of cortisol (CO), testosterone (TEST), human growth hormone (hGH), and thyroid hormones (T3, T4) were examined in eight trained weight lifters. Each subject completed two trials using a counterbalanced design: a control, no exercise trial (CON) and a heavy resistance exercise session of three sets of six exercises to exhaustion (RE). The exercise session took place between 1900 and 2000 hours. Blood was sampled prior to and at 20-min intervals after RE. For both trials blood was sampled at hourly intervals from 2100 hours until 0700 hours. The hGH and CO concentrations were increased up to 40-min post-exercise (P < 0.05), but returned to resting levels 1 h post-exercise. Nocturnal hGH concentration was not affected by RE (P > 0.26) and peaked at 0200 hours and declined until 0700 hours. Similarly, the CO responses were similar between the trails (P > 0.14). This CO concentrations declined from 2200 hours until 0100 hours, then increased steadily until 0700 hours. The TEST concentrations during both trials rose steadily from 2200 hours until 0700 hours; however, the rise in TEST from 0500–0700 hours during RE was greater than during the CON trails (P = 0.059). The T3 concentrations were unchanged by exercise and were similar at all times between trails. The T4 concentrations were elevated for 20 min after RE; however nocturnal T4 concentrations were lower after RE than during CON. These results would suggest that bGH and CO may have limited nocturnal reactivity to resistance exercise. However, the nocturnal alterations of TEST and T4 after resistance exercise, although small, may have implications for muscle anabolism. 相似文献
86.
Summary Five normal men performed seven sets of seven squats at a load equal to 80% of their seven repetition maximum. Plasma growth
hormone (GH) and lactate levels increased during and after the completion of the exercise. A significant (r=0.93, P<0.001) linear correlation was found between GH changes and the corresponding oxygen Demand/Availability (D/A) ratio expressed
by
(where f=[lactate at time x]/[lactate at time 0]). A retrospective examination of previously published data from our laboratory and others also demonstrated
the existence of a significant correlation between changes in plasma GH levels and the D/A ratios over a wide variety of exercise;
aerobic and anaerobic, continuous and intermittent, weight lifting and cycling, in both fit and unfit subjects under normoxic
and hypoxic conditions. It is suggested that the balance between oxygen demand and availability may be an important regulator
of GH secretion during exercise.
DCIEM No. 87-P-27 相似文献
87.
J. Caverzasio H. Murer H. Fleisch J. -P. Bonjour 《Pflügers Archiv : European journal of physiology》1982,394(3):217-221
Recent clearance studies have demonstrated that the maximal tubular reabsorption of inorganic phosphate (Pi) per ml of glomerular filtrate (max. TRPi/ml GF) of the whole kidney is markedly lower in adult than in young growing rats fed either normal (0.8 g%) or low (0.2 g%) phosphorus diet. In addition, in adult rats clearance studies indicate that enhancement of max. TRPi/ml GF is observed 21 days but not 8 days after starting the low (0.2%) phosphorus diet. In the present work we have studied in the same experimental condition the Na+-dependent Pi uptake in brush border membrane vesicles (BBMV) isolated from renal cortex of either young growing or adult rats. The results of this study indicate that under the low (0.2%) but not under the normal (0.8%) phosphorus diet the Na+-dependent Pi uptake by BBMV was significantly depressed in adult as compared to young growing rats. In adult rats the Pi transport response to Pi restriction monitored at the brush border membrane level was different from that observed by clearance studies in the whole kidney. Indeed, the Pi uptake by BBMV was already enhanced after 8 days of Pi restriction and it did not increase further when studied 21 days after starting the low (0.2%) phosphorus diet. These results suggest that the regulation of the overall transfer of Pi across the renal epithelium may involve other additional modulating factors than the Na+-dependent Pi transport system present in the luminal membrane of the proximal tubule. 相似文献
88.
新生儿血清瘦素水平变化与胰岛素和生长激素关系的研究 总被引:2,自引:0,他引:2
目的 探讨新生儿血清瘦素来源及其与胰岛素和生长激素的关系。方法 采用放射免疫法检测 80例新生儿静脉血和脐血瘦素水平 ,根据不同胎龄新生儿出生体重值分为大于胎龄儿 (LGA)组 2 8例 ,适于胎龄儿 (AGA)组 36例 ,小于胎龄儿 (SGA)组 16例 ;采用Rohrer′s指数 =出生体重 (g)× 10 0 /身长 (cm) 3 估测新生儿营养状态。结果 早产儿血清瘦素水平明显低于足月儿 (0 6 6± 1 0 3ng/mlvs 3 5 9± 2 16ng/ml,P <0 0 1) ;AGA儿血清瘦素水平 (3 0 6± 0 96ng/m1)明显低于LGA儿(4 0 3± 2 2 2ng/m1) ,而高于SGA儿 (1 13± 1 98ng/m1) ;足月新生儿血清瘦素水平与Rohrer′s指数、新生儿体重、胎龄 ,血清胰岛素、生长激素水平呈显著正相关。结论 新生儿体内瘦素主要来源于自身脂肪组织 ,它反映新生儿的生长营养状态 ,推测瘦素可能通过胰岛素、生长激素共同调节新生儿的生长发育 ,在胎儿和新生儿生长发育中起重要作用。 相似文献
89.
The hormonal responses of nine male, strength athletes to strength exercise were examined. The athletes performed one moderate-
and one high-intensity strength exercise workout. In the high-intensity workout, the load was 100% of each subject's three-repetition
maximum (3-RM) for squats and front squats, and 100% of each subject's six-repetition maximum (6-RM) for leg extensions. In
the moderate-intensity workout, the load was 70% of the high-intensity protocol. Rest periods between sets were 4–6 min for
both workouts. Blood samples were taken before, 30 min into, and every 15 min for the 1st h after exercise, and then 3, 7,
11, 22 and 33 h after exercise, thus allowing examination of both the acute and prolonged hormonal responses. Blood samples
were analyzed for testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), cortisol, adrenocorticotrophic
hormone (ACTH), growth hormone (GH), insulin-like growth factor (IGF-1), insulin, sex hormone binding globulin, creatine kinase,
total protein, glucose and lactate. The acute responses of testosterone and cortisol were greater during the high-intensity
protocol as compared to the moderate-intensity protocol. The cortisol response was associated with an increase in ACTH concentration.
LH and FSH showed no response to either protocol. Acute GH responses were not different between protocols. There were great
inter-individual differences in acute GH responses to both protocols. There were no significant differences between protocols
with regard to prolonged responses for any hormone. In both trials, IGF-1 concentrations were significantly lower at 0800 hours
the morning after exercise as compared to concentrations found at 0800 hours the morning before exercise. The mechanisms responsible
for reducing IGF-1 concentration in these trials are unclear, and it is not known if this reduction observed 22 hours after
exercise is of physiological significance.
Accepted: 13 December 1999 相似文献
90.
神经母细胞瘤是儿童期的常见恶性肿瘤之一。临床上,半数以上神经母细胞瘤有明显的N-myc癌基因扩增。神经生长因子(NGF)可使某些神经母细胞瘤细胞分化成神经元样的细胞。但对有N-myc扩增的神经母细胞瘤则可能因NGF受体缺乏而无明显促分化反应。本研究运用重组DNA技术将人NGF受体基因重组到有N-myc扩增,且NGF受体表达很低的神经母细胞瘤系(IMR-32)中,经克隆化培养、筛选,建立了稳定的细胞系—IMR-32/NGFR和对照细胞系IMR-32/NEO。经用抗NGFR的单克隆抗体检测用Flow cytometry技术证实IMR-32/NGFR系中有明显的NGF受体表达,而其母系IMR-32和空病毒对照系IMR-32/NEO则无表达迹象,说明NGF受体表达在IMR-32/NGFR系中是特异的,并能同抗NGFR单克隆抗体特异结合。用Northern B10ting技术亦测得IMR-32/NGFR中NGFR的mRN A明显表达。而其母系IMR-32和对照系IMR-32/NEO则无明显表达。这说明IMR-32/NGFR系中NGFR在mRNA水平上亦是特异的。N-myc和K-ras癌基因在IMR-32、IMR-32/NEO、IMR-32/NGFR三系中无明显变化。在NGF处理后,形态上三系均无明显的分化迹象。但IMR-32/NGFR在神经原纤维轻链的表达上轻度增高。c-fos癌基因的表达见于所有三个细胞系,IMR-32/NGFR略强些。这些说明,在恢复了NGFR基因和表达之后,对N-myc和K-ra 相似文献