Optimization Of The Technology For Producing A Magneto Controllable Nanocomposite Ag@Fe3o4 Using Mathematical Design

Objective: The purpose of the research was to optimize technology for producing a magneto controllable nanocomposite Ag@Fe3O4 with modern physicochemical and therapeutic requirements using methods of mathematical design of the experiment. Methods: To optimize the synthesis process of the nanocomposite Ag@Fe3O4, the method of factor experiment was used. Mathematical calculations were performed using the STATISTICA 10 StatSoft Inc. system and Excel spreadsheet processor of MS Office 2019 Professional Plus. Results: Based on the study of technological parameters of nanocomposite synthesis Ag@Fe3O4 (16 experiments) a regression equation was obtained: Y = 106.415+0.038X1+4.448Х2+1.806Х3–1.593Х4–18.945Х5–109.980Х6. By the use of this equation the synthesis parameters were optimized with the help of steepest ascent method. It was found that the maximum yield of Ag@Fe3O4 can be achieved under the following conditions: X1 (magnetite synthesis time, min)–40; X2 (glucose content in solution,%)–10; X3 (temperature of the Tollens reaction, °С)–65; X4 (magnetite silver coating time, min)–30; X5 (pH, units)–8.5; X6 (rate of addition of ammonia, mol/min)–0.36. Conclusion: Using mathematical design of the experiment, a technology was developed for producing Ag@Fe3O4 with modern physicochemical and therapeutic requirements.

Food-borne nitrates and nitrites as a cause of methemoglobinemia.

Methemoglobinemia is a potentially fatal condition. Previous reports of toxic methemoglobinemia due to food-borne nitrates and nitrites are reviewed. Contamination of food during manufacture or degradation of nitrates in vegetables appear to be the most important factors. Some food items, such as refrigerated "dim-sum", stuffed pork and Chinese sausages, are very popular among some Asian populations; a stringent control against the excessive use of nitrates and nitrites is required in order to prevent outbreaks of toxic methemoglobinemia. Patients with glucose-6-phosphate dehydrogenase deficiency, a common condition in some Asian populations, may present with methemoglobinemia and intravascular hemolysis following exposure to oxidant drugs or chemicals. Methylene blue is inefficient and may exacerbate hemolysis in these patients; partial exchange transfusion may be required.

Peripheral blood lymphocyte subsets after allogeneic bone marrow transplantation: reconstitution and correlation with the occurrence of acute graft-versus-host disease.

Peripheral blood lymphocyte subsets were enumerated at regular intervals during the first year after allogeneic bone marrow transplantation (BMT) in 21 Chinese patients. Eight of these patients had acute graft-versus-host disease (GVHD) while they were assessed at the time of engraftment. Our results show in patients receiving allogeneic BMT: (1) T and NK cells were the predominant lymphocyte subsets in the early reconstitution stage while B cells were severely depleted; (2) absolute numbers of the major lymphocyte subsets normalised in 4-5 months; (3) an increased percentage of T cells that expressed the activation antigen HLA-DR and a reversed CD4:CD8 ratio were observed throughout the first 12 months after BMT; (4) patients with acute GVHD had significantly higher white cell count and NK cell percentage than those not complicated by acute GVHD.

Hospital admissions due to acute poisoning in the New Territories, Hong Kong.

To study the pattern of acute poisoning in the New Territories East of Hong Kong, 291 adult cases admitted to the Prince of Wales Hospital in 1989 were reviewed. The female-to-male ratio was 2.3 to 1 and the majority of patients (83%) were below the age of 40. The main poisons involved were hypnotics and sedatives (44.3%), household products (14.8%) and analgesics (10%). The poisoning was intentional in the majority of cases (98.6%). A specific antidote was necessary in 5.2% of cases. Four patients died after admission giving an overall mortality of 1.4%. When compared to the findings from other western countries, important variations in the pattern of acute poisoning were seen in Hong Kong. Firstly, a substantial proportion of drugs ingested were not dispensed labeled although their nature could usually be determined. Secondly, "Dettol", a household antiseptic, was commonly used in self-poisoning episodes. The lack of drug identification labeling on dispensed medicines outside hospitals is of great concern to all physicians in Hong Kong.

Hospitalizations due to acute pesticide poisoning in Hong Kong.

A review of 43 adult cases of pesticide poisoning admitted to the Prince of Wales Hospital in Hong Kong shows that acute exposures to pesticides are more often due to parasuicide (77%) than to accidents (23%). Most accidents are caused by contaminated green leafy vegetables. Serious intoxications or complications were seen in 11 patients (26%). Of the five fatalities, four were due to paraquat.

Disease profiles in Chinese in Hong Kong: an analysis of the primary diagnoses in 561 acute hospital medical admissions.

Little is known about the disease profiles in Chinese living in an urbanized community like Hong Kong. Accordingly, the discharge summaries of 561 acute hospital medical admissions were reviewed and the primary diagnoses (the main reason for admission or the most important clinical problem) were coded according to the International Classification of Diseases. Our data indicate that cardiovascular diseases are the most important cause of acute medical admissions and mortality and that gastrointestinal hemorrhage is very common amongst the Chinese in Hong Kong.

Clinical features and hospital management of bites by the white-lipped green pit viper (Trimeresurus albolabris).

The clinical features and hospital management of 31 patients who were bitten by the white-lipped green pit viper (Trimeresurus albolabris) in Hong Kong are reviewed. The cardinal features in these patients were local pain and swelling and mild coagulation abnormalities. Hospital management should include prophylaxis against tetanus, analgesics and measures to reduce local effects such as elevation of the limb. The benefits of the use of prophylactic antibiotics remain to be established. Severe coagulation disturbances were uncommon and responded to fresh frozen plasma and platelet transfusion.

Hypercalcemia in active pulmonary tuberculosis and its occurrence in relation to the radiographic extent of disease.

The prevalence of hypercalcemia in tuberculosis in Hong Kong and its occurrence in relation to the radiographic extent of disease were studied in 57 patients with sputum smear (n = 44) and/or culture positive (n = 13) pulmonary tuberculosis and in five patients with military tuberculosis prior to treatment. Only one (1.6%) patient had a corrected plasma calcium level above the reference range for our laboratory. There was a positive relationship between the corrected plasma calcium levels and the radiographic extent of disease (r = 0.37), p < 0.01). As the occurrence of hypercalcemia in tuberculosis is known to be influenced by the calcium intake, our finding of a low prevalence of "absolute" hypercalcemia in Hong Kong could be related to the low dietary calcium intake in these subjects.

Virulence and antigenic properties of Rickettsia tsutsugamushi in a naturally infectei laboratory colony of Leptotrombidium (leptotrombidium) arenicola.

Over 1,200 isolations of R. tsutsugamushi were obtained over 7 generations of L. (L.) arenicola and no reproducible differences in virulence or antigenic markers could be detected among these isolations. The F8 generation yielded rickettsia with the same antigenic makeup and virulence properties as the original female parent mite. When these isolates were inoculated into mice they elicited the same predominant antibody specificities, i.e. they all produced antibody which reacted with the TA 763 and Karp strains. These were the same as the major antigens detected by direct fluorescent antibody staining of the isolates.