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Biomedical subjects

G Guo

Publications and source records attributed to G Guo.

47 records · Page 3Linked to original sources
PubMed1995

[The change in tissue oxygenation after severe steam inhalation injury].

Tissue oxygenation was observed in dogs inflicted with steam inhalation injury in this study. Main findings were as follows: there was significant decrease in cardiac output (CO), oxygen delivery (DO2), alveolar oxygen partial pressure (PAO2), arterial oxygen partial pressure (PaO2), mixed venous oxygen partial pressure (PVO2), arterial oxygen saturation (SaO2), mixed venous oxygen saturation (SVO2), and pH (P < 0.01), and marked increase in P(A-a)O2, oxygen extraction ratio (ERO2), and arterial carbon dioxide partial pressure (PaCO2) (P < 0.01 and P < 0.05). However there was no obvious change in oxygen consumption rate (VO2) within four hours after inhalation injury. The results indicated that the tissue hypoxia was caused directly by insufficient blood perfusion and oxygen supply as well.

Animals↗
PubMed1993

Optimal design of a six-bar linkage with one degree of freedom for an anthropomorphic three-jointed finger mechanism.

This research concerns the design of a three-jointed, anthropomorphic, finger mechanism for use as a prosthesis or robotic end-effector. Based on a study of finger configurations for the human hand, a six-bar linkage with one degree of freedom is proposed. A model of the fingertip displacement of the mechanism is derived by a vector analysis approach. The effects of joint friction on the transmission efficiency are analysed. By measuring the joint positions of a human finger, a mathematical model of the pinching and holding configurations are developed. Optimal parameters for the finger mechanism are obtained by non-linear programming based on an objective functional involving motion posture and locus, transmission efficiency and weight subject to geometric and bionic constraints. Simulation results indicate that the mechanism is useful for a variety of prosthetic and robotic applications.

Biomechanical Phenomena↗
PubMed1993

Event-history analysis for left-truncated data.

"This paper aims at providing a practical guidance for coping with social science event-history data that are left-truncated, especially when the length of exposure prior to observation is known. Only the case of single events is treated, although much of the discussion should be applicable to the case of repeated events, in which only the first spell is likely to be left-truncated. Marital dissolution data from the Panel Study of Income Dynamics (PSID) are used as an example...."

Americas↗
PubMed1993

Cavitation threshold with respect to dP/dt: evaluation in 29 mm bileaflet, pyrolitic carbon heart valves.

A total of 15 bileaflet mechanical heart valves were studied in a pulse duplicator at the Helmholtz Institute (Aachen, Germany) under conditions approximating first, a physiological pressure curve and subsequently, a sinusoidal pressure curve. In this study Edwards-Duromedics valves of the modified specification were compared with the earlier version of the Edwards-Duromedics valve as well as with St. Jude Medical valves. Each valve was tested at a series of nine (9) conditions. At each condition, without altering the valve installation or the systemic conditions, each valve was filmed by two separate video systems: the Helmholtz Institute strobe light system and a high speed video recording system. All data, as recorded by each system, was then independently analyzed by both of the two contributing groups and subsequently compared. In this manner, it was possible to objectively verify not only the consistency of the data obtained, but to also determine the relative reliability of the methods for cavitation threshold detection.

Carbon↗
PubMed1993

Use of sibling data to estimate family mortality effects in Guatemala.

This paper examines the potential bias in estimates of child mortality determinants produced by the questionable assumption that sibling data are independent, and estimates the unmeasured familial effects shared among siblings. The parameter estimates yielded by the multivariate hazard model are very similar to those yielded by the standard hazard model. The standard errors of the parameter estimates, however, tend to be underestimated in conventional analyses. The contribution to child mortality from the familial factors seems modest net of household socioeconomic status, at least in this Guatemalan data set.

Birth Order↗
PubMed1992

[A clinical research on mental disability of chronic schizophrenia. 202 cases report].

202 cases of chronic schizophrenia were investigated to determine the order of severity of mental disability. 112 cases were male and 90 cases were female. The average age of the cases was 51.7 +/- 3.4 years, the onset age of the disease was 22.9 +/- 6.9 years. In order to measure the severity, we worked out "Social Disability Screening Schedule for In-patients" (SDSS-I) based on "Social Disability Screening Schedule" offered by WHO. 202 cases were measured with SDSS-I, the results showed that 6 cases were slight, 22 cases were mild, 66 cases were severe and 108 cases were profound. Most part of the cases (86.7%) were severely and profoundly mentally disabled.

Activities of Daily Living↗
PubMed1991

Clenbuterol, a beta 2-receptor agonist, reduces net bone loss in denervated hindlimbs.

Clenbuterol treatment for several weeks prevented up to one-third of the reduction in mineralization of femurs and tibias caused by sectioning of the sciatic nerve in young rats. The normalizing effect of clenbuterol on bone mineral content was directly proportional to similar alterations in muscle mass, which in turn could be abolished by ablation of the triceps surae or hindlimb unweighting and reduced by hypophysectomy. In contrast to the effects of inactivity, ovariectomy caused small reductions (2-4%) in bone density that were not affected by clenbuterol and were not accompanied by changes in ash weight. Together, our results suggest that the ability of beta 2-agonists to retard the loss in net muscle mass and enhance contractile tension can oppose net bone loss caused by denervation. Increases in contractile tension caused by beta 2-agonists may enhance the utility of exercise or electrical stimulation as countermeasures for the effects of scoliosis, prolonged bed rest, spinal cord injury, or weightlessness in space on bone mass.

Adrenergic beta-Agonists↗
PubMed1991

The use of new model life tables at very low mortality in population projections.

"New model life tables have been calculated...modifying the regional model life tables by Coale, Demeny and Vaughan published in 1983.... The purpose of the present article is not to repeat the description of the construction of the tables but to provide a systematic procedure for their use in projecting mortality into the future in low-mortality populations. The new model life tables incorporate age patterns of mortality that conform quite closely to the patterns in the lowest mortality populations yet on record and present extrapolated schedules that include systematic extensions of recent changes in age-specific mortality rates."

Age Factors↗