Dynamic stiffness method for free vibrations analysis of partial fluid-filled orthotropic circular cylindrical shells

Free vibrations of partial fluid-filled orthotropic circular cylindrical shells are investigated using the Dynamic Stiffness Method (DSM) or Continuous Element Method (CEM) based on theFirst Order Shear Deformation Theory (FSDT) and non-viscous incompressible fluid equations. Numerical examples are given for analyzing natural frequencies and harmonic responses of cylindrical shells partially and completely filled with fluid under various boundary conditions. The vibration frequencies for different filling ratios of cylindrical shells are obtained and compared with existing experimental and theoretical results which indicate that the fluid filling can reduce significantly the natural frequencies of studiedcylindrical shells. Detailed parametric analysis is carried out to show the effects of some geometrical and material parameters on the natural frequencies of orthotropic cylindrical shells. The advantages of this current solution consist in fast convergence, low computational cost and high precision validating for all frequency ranges

Intensified Antituberculosis Therapy in Adults with Tuberculous Meningitis

BACKGROUND Tuberculous meningitis is often lethal. Early antituberculosis treatment and adjunctive treatment with glucocorticoids improve survival, but nearly one third of patients with the condition still die. We hypothesized that intensified antituberculosis treatment would enhance the killing of intracerebral Mycobacterium tuberculosis organisms and decrease the rate of death among patients. METHODS We performed a randomized, double-blind, placebo-controlled trial involving human immunodeficiency virus (HIV)-infected adults and HIV-uninfected adults with a clinical diagnosis of tuberculous meningitis who were admitted to one of two Vietnamese hospitals. We compared a standard, 9-month antituberculosis regimen (which included 10 mg of rifampin per kilogram of body weight per day) with an intensified regimen that included higher-dose rifampin (15 mg per kilogram per day) and levofloxacin (20 mg per kilogram per day) for the first 8 weeks of treatment. The primary outcome was death by 9 months after randomization. RESULTS A total of 817 patients (349 of whom were HIV-infected) were enrolled; 409 were randomly assigned to receive the standard regimen, and 408 were assigned to receive intensified treatment. During the 9 months of follow-up, 113 patients in the intensified-treatment group and 114 patients in the standard-treatment group died (hazard ratio, 0.94; 95% confidence interval, 0.73 to 1.22; P=0.66). There was no evidence of a significant differential effect of intensified treatment in the overall population or in any of the subgroups, with the possible exception of patients infected with isoniazid-resistant M. tuberculosis. There were also no significant differences in secondary outcomes between the treatment groups. The overall number of adverse events leading to treatment interruption did not differ significantly between the treatment groups (64 events in the standard-treatment group and 95 events in the intensified-treatment group, P=0.08). CONCLUSIONS Intensified antituberculosis treatment was not associated with a higher rate of survival among patients with tuberculous meningitis than standard treatment. (Funded by the Wellcome Trust and the Li Ka Shing Foundation; Current Controlled Trials number, ISRCTN61649292.)

Oseltamivir Is Adequately Absorbed Following Nasogastric Administration to Adult Patients with Severe H5N1 Influenza

In the absence of a parenteral drug, oral oseltamivir is currently recommended by the WHO for treating H5N1 influenza. Whether oseltamivir absorption is adequate in severe influenza is unknown. We measured the steady state, plasma concentrations of nasogastrically administered oseltamivir 150 mg bid and its active metabolite, oseltamivir carboxylate (OC), in three, mechanically ventilated patients with severe H5N1 (male, 30 yrs; pregnant female, 22 yrs) and severe H3N2 (female, 76 yrs). Treatments were started 6, 7 and 8 days after illness onset, respectively. Both females were sampled while on continuous venovenous haemofiltration. Admission and follow up specimens (trachea, nose, throat, rectum, blood) were tested for RNA viral load by reverse transcriptase PCR. In vitro virus susceptibility to OC was measured by a neuraminidase inhibition assay. Admission creatinine clearances were 66 (male, H5N1), 82 (female, H5N1) and 6 (H3N2) ml/min. Corresponding AUC0–12 values (5932, 10,951 and 34,670 ng.h/ml) and trough OC concentrations (376, 575 and 2730 ng/ml) were higher than previously reported in healthy volunteers; the latter exceeded 545 to 3956 fold the H5N1 IC50 (0.69 ng/ml) isolated from the H5N1 infected female. Two patients with follow-up respiratory specimens cleared their viruses after 5 (H5N1 male) and 5 (H3N2 female) days of oseltamivir. Both female patients died of respiratory failure; the male survived. 150 mg bid of oseltamivir was well absorbed and converted extensively to OC. Virus was cleared in two patients but two patients died, suggesting viral efficacy but poor clinical efficacy

An Outbreak of Severe Infections with Community-Acquired MRSA Carrying the Panton-Valentine Leukocidin Following Vaccination

Background: Infections with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are emerging worldwide. We investigated an outbreak of severe CA-MRSA infections in children following out-patient vaccination. Methods and Findings: We carried out a field investigation after adverse events following immunization (AEFI) were reported. We reviewed the clinical data from all cases. S. aureus recovered from skin infections and from nasal and throat swabs were analyzed by pulse-field gel electrophoresis, multi locus sequence typing, PCR and microarray. In May 2006, nine children presented with AEFI, ranging from fatal toxic shock syndrome, necrotizing soft tissue infection, purulent abscesses, to fever with rash. All had received a vaccination injection in different health centres in one District of Ho Chi Minh City. Eight children had been vaccinated by the same health care worker (HCW). Deficiencies in vaccine quality, storage practices, or preparation and delivery were not found. Infection control practices were insufficient. CA-MRSA was cultured in four children and from nasal and throat swabs from the HCW. Strains from children and HCW were indistinguishable. All carried the Panton-Valentine leukocidine (PVL), the staphylococcal enterotoxin B gene, the gene complex for staphylococcal-cassette-chromosome mec type V, and were sequence type 59. Strain HCM3A is epidemiologically unrelated to a strain of ST59 prevalent in the USA, althoughthey belong to the same lineage. Conclusions. We describe an outbreak of infections with CA-MRSA in children, transmitted by an asymptomatic colonized HCW during immunization injection. Consistent adherence to injection practice guidelines is needed to prevent CA-MRSA transmission in both in- and outpatient settings

Legal-Onto: An ontology-based model for representing the knowledge of a legal document

In the legal knowledge domain, legal norm documents are general rules which are mandatory for people in a certain field. Many regulations are affecting to activities in a field. Ontology is an effective approach for representing practical knowledge domains. In this paper, an integration ontology for representing the knowledge of a law document is proposed. This model is integrated of ontology about relational knowledge and the graph of keyphrases as a conceptual graph. It can represent semantic of contents in the law document. Based on this integrated model, the improvement method of self-attention network by language-oriented semantic analyzing is studied for intellectual retrieval on the law document. Moreover, the proposed method is applied to construct an intelligent support system for knowledge querying on Vietnam Land Law. It can help users to query some meaning of terminology in land law and some land-related administrative procedures

Generative AI, why, how, and outcomes: A user perspective

Drawing on the extended Unified Theory of Acceptance and Use of Technology (UTAUT2) and Task-Technology Fit (TTF) theory, we developed a unique research model to explore the factors affecting ChatGPT use and the main activities individuals do while using ChatGPT, and determine whether they continue using ChatGPT and recommend it to others. The moderating role of curiosity in the relationships between various influencing factors and ChatGPT use was also examined. We conducted a quantitative research with the data collected from 671 users in Vietnam. The results indicated that (1) the majority of the dimensions of UTAUT2 and TTF affect ChatGPT use. However, interestingly, contrary to our expectation, effort expectancy, social influence, and trust have no effect on ChatGPT use, (2) ChatGPT use directly influences intention to continue using ChatGPT and word-of-mouth (WOM), (3) intention to continue using ChatGPT has a significant effect on WOM, and (4) curiosity acts as a moderator on only three paths from hedonic motivation, facilitating conditions, and performance expectancy to ChatGPT use. The originality of this study lies in (1) a unique research model by combining the UTAUT 2 and the TTF inclusive of trust and curiosity, and (2) enriching understanding of the users’ behavioral process in technology adoption by examining a comprehensive process, namely actual usage–continuance intention to use–recommending. Practical implications for ChatGPT providers, policymakers, and business marketers are also discusse

Generative AI, why, how, and outcomes: A user perspective

Drawing on the extended Unified Theory of Acceptance and Use of Technology (UTAUT2) and Task-Technology Fit (TTF) theory, we developed a unique research model to explore the factors affecting ChatGPT use and the main activities individuals do while using ChatGPT, and determine whether they continue using ChatGPT and recommend it to others. The moderating role of curiosity in the relationships between various influencing factors and ChatGPT use was also examined. We conducted a quantitative research with the data collected from 671 users in Vietnam. The results indicated that (1) the majority of the dimensions of UTAUT2 and TTF affect ChatGPT use. However, interestingly, contrary to our expectation, effort expectancy, social influence, and trust have no effect on ChatGPT use, (2) ChatGPT use directly influences intention to continue using ChatGPT and word-of-mouth (WOM), (3) intention to continue using ChatGPT has a significant effect on WOM, and (4) curiosity acts as a moderator on only three paths from hedonic motivation, facilitating conditions, and performance expectancy to ChatGPT use. The originality of this study lies in (1) a unique research model by combining the UTAUT 2 and the TTF inclusive of trust and curiosity, and (2) enriching understanding of the users’ behavioral process in technology adoption by examining a comprehensive process, namely actual usage–continuance intention to use–recommending. Practical implications for ChatGPT providers, policymakers, and business marketers are also discusse

Scalable, low-cost, and versatile system design for air pollution and traffic density monitoring and analysis

Vietnam requires a sustainable urbanization, for which city sensing is used in planning and de-cision-making. Large cities need portable, scalable, and inexpensive digital technology for this purpose. End-to-end air quality monitoring companies such as AirVisual and Plume Air have shown their reliability with portable devices outfitted with superior air sensors. They are pricey, yet homeowners use them to get local air data without evaluating the causal effect. Our air quality inspection system is scalable, reasonably priced, and flexible. Minicomputer of the sys-tem remotely monitors PMS7003 and BME280 sensor data through a microcontroller processor. The 5-megapixel camera module enables researchers to infer the causal relationship between traffic intensity and dust concentration. The design enables inexpensive, commercial-grade hardware, with Azure Blob storing air pollution data and surrounding-area imagery and pre-venting the system from physically expanding. In addition, by including an air channel that re-plenishes and distributes temperature, the design improves ventilation and safeguards electrical components. The gadget allows for the analysis of the correlation between traffic and air quali-ty data, which might aid in the establishment of sustainable urban development plans and poli-cies

Modeling and optimization of the orange leaves oil extraction process by microwave-assisted hydro-distillation : the response surface method based on the central composite approach (RSM-CCD model)

Although being a by-product after the harvest, orange leaves could be used to produce essential oil through extraction. Application of the essential oil extracted from orange leaves is diverse ranging from food flavoring to cosmetics. This study aimed to develop optimal conditions for microwave assisted hydro-distillation of essential oil from orange leaves. The selected optimization method is Response Surface Methodology in conjunction with the central composite experiment design. The factors that were varied for the production of the orange leaves oil extraction were material-to-water ratio, extraction time, and microwave power. Accordingly, a statistical model was established and Analysis of variance (ANOVA) was carried out to identify the set of factors that gives the highest essential oil yield. Optimization results revealed optimal conditions as follows, material and water ratio of 3.46:1 (mL/g), extraction time of 100.47 min and operating power of 471.58 W. These conditions correspond to the essential oil yield of 0.43% with 92.1 % reliability. In addition, we also analyze the produced essential oils by gas chromatography-mass spectrometry (GC-MS). The GC-MS results revealed that major components of essential oil were Sabinene (30.556 %), Cis-Ocimene (10.139 %), and D-Limonene (9.682 %)