Experimental study of high-frequency two-way jet ventilation

BACKGROUND AND METHODS

A new mode of jet ventilation, high-frequency two-way jet ventilation, was devised and introduced to increase CO2 elimination. High-frequency two-way jet ventilation was achieved by adding reverse jet pulses inside the trachea through an intratracheal reverse jet system to the expiratory phase of common high-frequency jet ventilation. The ventilatory efficiency and features of high-frequency two-way jet ventilation were investigated and compared with those features of high-frequency jet ventilation in ten dogs in the same experimental condition. Random sample selection and randomized crossover trial were used for comparison between high-frequency two-way jet ventilation and high-frequency jet ventilation. Peak inspiratory pressure, end-expiratory pressure, and the arterial blood gas variables (PaO2, PaCO2, and pH) were measured during the study.

RESULTS

PaCO2 with high-frequency two-way jet ventilation was about 35% lower than that with high-frequency jet ventilation (from 45 to 29 torr [6.0 to 3.9 kPa], p less than .01). Simultaneously, peak inspiratory pressure and end-expiratory pressure during high-frequency two-way jet ventilation were significantly lower than those same variables measured during high-frequency jet ventilation. End-expiratory pressure of high-frequency two-way jet ventilation was a negative pressure (-2.45 +/- 0.45 cm H2O). The pH of high-frequency two-way jet ventilation was significantly higher than that of high-frequency jet ventilation.

CONCLUSIONS

Compared with high-frequency jet ventilation, high-frequency two-way jet ventilation demonstrated a ventilatory feature of increasing CO2 elimination and simultaneously decreasing airway pressure.

Personal characteristics of Chinese children and their discrepancies: a report on children's development in Anhui (I)

The authors report on a 1990 survey on the characteristics of children in China which included 1,000 primary school pupils in Anhui Province. The focus is on differences between only children and those with brothers or sisters. The results suggest that "the development of temperaments, moral character, behavior and basic ability of primary school pupils in Anhui is generally healthy despite certain discrepancies among different types of children."

The threshold of survival for system of two species in a polluted environment

The effects of toxicants on naturally stable two-species communities are studied. Persistence-extinction thresholds are given for populations in the toxicant stressed Lotka-Volterra model of two interacting species. The threshold results are expressed in terms of relationships involving the population intrinsic growth rates, dose-response parameters, and interaction rates.

[Observation on the epidemiologic efficacy for 9 years on epidemic meningococcal polysaccharide vaccine of group A by district immunization method]

According to previous studies, there might be a peak of epidemic meningitis in Baoding City in 1984. For preventing the epidemic, we carried out vaccination with meningococcal polysaccharide vaccine by district immunization method during the 1980-1984 and then vaccination only to the children aged 12-24 months every year. The vaccination rate was 80.01% in 1980-1984 and was 97.15% in 1985-1988. During the 9 years, 833,377 children of vaccination group were observed, 4 of whom developed this disease, with an incidence of 0.48/100,000; and 304,085 children in the control group were observed, 25 of whom contracted this illness, with an incidence of 8.22/100,000. The protective rate of vaccine was 94.16% and the efficacy index was 1:17.12. This result showed that peak year of epidemic meningitis predicted in 1984 was prevented by vaccine immunization and the incidence of this disease was continuously kept less than 1/100,000 for 9 years.

A Chinese female postnuptial leaving home model--a procedure for analyzing main parameters alpha and beta in the setting up, testing and estimation of the model

"The first section of this article...sets up a model for leaving home after marriage that is suited to China's situation. The second section performs a statistical test and verification of the formulated model for leaving home after marriage. The third section...proposes a method for analyzing the main parameters...in the model...." The model is set up along the lines of the Brass-Gompertz relational fertility model.

Intestinal metaplasia and gastric carcinoma. A histochemical and immunohistochemical study

This article sums up the histochemical and immunohistochemical study of 55 cases of gastric carcinoma and 21 controls with benign gastric lesions. The results showed most of the adjacent mucosa of gastric carcinoma developed incomplete type intestinal metaplasia (IM). The percentage of Type IIb (ie, secreting sulphomucin) reached 72.5%. In most cases, high iron diamine (HID) rose in cancerous tissue and concomitantly in the IM epithelium of the adjacent gastric carcinoma. The phenomena of separation condition of HID+ in cancerous tissue, HID- in IM epithelium surrounding carcinoma, or HID- in cancerous cell but HID+ in IM of the surrounding epithelium of carcinoma, were much fewer. The two kinds of mucin antigen distribution were observed simultaneously. In the control and gastric carcinoma groups, neither large intestinal mucin antigen (LIMA) nor small intestinal mucin antigen (SIMA) could be detected in the normal epithelium of gastric mucosa. SIMA was mainly found in the goblet cells of IM and the mucous cells of columnar epithelium, while LIMA was mainly present in the columnar cells, in luminal border and/or in goblet cells. LIMA in the carcinoma group is apparently higher than that in the controls. The percentage of LIMA+ in the IM epithelium of adjacent gastric carcinoma and that in carcinoma cells were also raised in most cases. All these demonstrated a close relationship between IM and gastric carcinoma. Our results also showed that not only HID+, but also LIMA+ may represent a precancerous lesion in gastric carcinoma.

[Investigation on resources of the Chinese drug beimu in Gansu Province]

Based on a resources investigation and taxonomic research on the medicinal plants of Fritillaria from Gansu Province. Nine species one variety and one cultivation variety have been reported. Records and distribution of the species, together with a key for the species and a key for the powdered drug have been furnished as well.

Persistence and extinction of a population in a polluted environment

Models of the persistence and extinction of a population or community in a polluted environment have been investigated in several papers. But all of those papers have a basic assumption that the capacity of the environment is so large that the change of toxicants in the environment that comes from uptake and egestion by the organisms can be neglected. This assumption is not made in this article. Some sufficient conditions on persistence or extinction of a population have been obtained, and the threshold between the two has also been obtained for most situations.

[Acute toxicity of flesh oil of Hippophae rhamnoides L. and its protection against experimental hepatic injury]

Protection by flesh oil of Hippophae rhamnoides against hepatotoxicity induced by CCl4 and acetaminophen (AAP) is reported in this paper. It was found that the oil markedly inhibited MDA formation of liver induced by CCl4 and AAP, decreased sGPT levels induced by CCl4 and blocked depletion of GSH damaged liver induced by AAP.LD50 greater than 45.0 g/kg.

[Short-term curative effect of cultured Cordyceps sinensis (Berk.) Sacc. Mycelia in chronic hepatitis B]

33 cases of chronic hepatitis B. patients treated with cultured Cordyceps sinensis mycelia have shown that the drug improves the liver function, promotes negative transfer HBsAg, and markedly helps to raise plasma albumin, resist high gamma globulin and to adjust body immunocompetence. It is therefore suggested that cultured Cordyceps sinensis mycelia may be used as a medicine for chronic hepatitis B. patients in adjusting protein metabolism and correcting inversion of albumin and globulin.

Long-pulsewidth pulsed Nd:YAG laser

A several millisecond pulsewidth pulsed Nd:YAG laser with output power of 200 W average and 5000 W peak is developed, and its performance is investigated. The experimental results are taken as a guide to designing and constructing a long-pulsewidth pulsed laser with high average output power.