GROUND WATER POLLUTION AT THE NORTHERN PART OF HOCHIMINH CITY

Joint Research on Environmental Science and Technology for the Eart

Effect of Molecular Charge Asymmetry on Even-to-odd Ratio of High-order Harmonic Generation

Recently, asymmetric molecules, such as HeH$_2^+$, CO, OCS, HCl, have been evolved much attention since its rich information in the high-order harmonic generation (HHG), whose ratio of adjacent even and odd harmonics characterizes the asymmetry of molecules. In this paper, we study the dependence of even-to-odd ratio on the asymmetric parameters, in particular, the nuclear-charge ratio, and the permanent dipole, by exploiting a simple but general model of asymmetric molecules $Z_1Z_2$ subjected to an intense laser pulse. The HHG is simulated by the numerical method of solving the time-dependent Schrödinger equation. We find out that this even-to-odd ratio strongly depends on the nuclear-charge ratio. In particular, the even-to-odd ratio reaches its maximum when the nuclear-charge ratio is about from 0.5 to 0.7. Besides, the dependence on the permanent dipole of the even-to-odd ratio has a non-trivial law. To explain, we calculate the analytical ratio of the transition dipole according to the emission of even and odd harmonics, and this ratio is well consistent with the even-to-odd ratio of the HHG

Dengue Haemorrhagic Fever in the South of Vietnam during 1975-1992 and Its Control Strategy

The incidence of dengue (DEN) virus infection in Vietnam has increased dramatically in the past 30 years. From 1960 up to now, the number of dengue haemorrhagic fever (DHF) cases has been continuing to increase and recorded as the greatest one in Southeast Asia and the Western Pacific Regions. DHF was endemic in South Vietnam and 30-380 cases/100,000 population were reported annually. Major epidemics have occurred in a 3-4 years frequency, as in 1975, 1978-1979, 1983 and 1987. The 1987 outbreak was the largest one with 83,905 cases and 904 deaths. DHF epidemics usually took place from June to November every year. The peak transmission was recorded in July-August and September, coinciding with the rainy season and the breeding period of Aedes aegypti. The majority of confirmed cases was children of 5-6 year-old-group, in which there was no sex difference. In the virological surveillance in Ho Chi Minh City and in some surrounding provinces, several DEN virus strains were isolated from patients\u27 blood as well as from the mosquitoes. In the 1987 DHF outbreak, DEN-2 was the dominant sero-type (90.5%). But from 1990 the epidemic sero-type has changed, DEN-1 was introduced and was continuing to grow-up (58%). Then in 1992 outbreak, the DEN-2 was reintroduced, from 26.3% in 1991 has increased to 41.4%. Serological investigation of healthy persons in 12/17 southern provinces had demonstrated that there were relatively wide circulations of DEN, Japanese encephalitis (JE) and chikungunya (Chik) viruses and the endemic strains of DEN were found different in some studied areas. There had been augmentation of primary infection rate and decrease of the susceptibility rate in children prior to the DHF epidemic. Seven JE virus strains were isolated from dengue fever (DF) patients\u27 blood. This fact has introduced as a new concept in the isolation of JE virus. In the final pant of the report, the authors stressed on the "Active surveillance" as a new strategy for controlling the DHF epidemic in South Vietnam. The goal of this active surveillance is to have early warning and predictive capability for epidemic dengue, based on serological and clinical surveillance. Because dengue cases were detected in January-February of every year, so the base line is: when first cases of DF/DHF were detected, it needs to be promptly implemented the larval control and insecticide must be sprayed around the patient\u27s houses. But now almost Provincial Centers of Hygiene and Epidemiology often waited and when big DHF epidemic had already occurred, they started to implement its control measures, so it is too late to control the DHF outbreak

Current Situation of Japanese Encephalitis in the South of Vietnam, 1976-1992

Cases of "Acute Encephalitis Syndrome (AES)" and deaths were reported annually in all 17 provinces in the South of Vietnam. The highest morbidity of 936 patients was recorded in 1980, while highest mortality of 339 deaths in 1977. The lowest figures of morbidity was 197 cases in 1990 and lowest mortality was 34 deaths in 1985. Sporadic cases were reported throughout the year but small outbreaks with low peaks were seen in February and July annually. Twenty five strains of Japanese encephalitis (JE) virus were isolated during 1978-1992: 8 from patients\u27 blood, 5 from cerebrospinal fluid (CSF), 9 from Culex quinquefasciatus, 3 from Aedes aegypti. Serologically confirmed JE cases were not many, because most of the human sera sent to us for testing were used for differential diagnosis of pernicious malaria. The anti-JE antibody prevalence among healthy human in 11/17 provinces was found to be extremely high, especially in adults. The antibody positive rate among swine to JE was found to be high: 82% with GMT 65.2 in 189 sera taken at My Tho-Tien Giang province in March 1978 and 77.4% with GMT 49.7 in 261 sera taken in the vicinity of Ho Chi Minh City in September 1992. From the above data, the Southern part of Vietnam is an endemo-epidemic area of JE virus infection

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke