Drug resistance evolution in patients with human immunodeficiency virus-1 under long-term antiretroviral treatment-failure in Yunnan Province, China.

BACKGROUND: Understanding the prevalence and evolution of HIV-1 drug resistance (DR) and associated mutation patterns is critical to implementing free antiretroviral therapy in Yunnan, the first antiretroviral treatment location in China. Here We provide a basis for understanding the occurrence and development of HIV-1 resistance in Yunnan and a theoretical foundational for strategy to delay HIV-1 drug resistance and achieve successful individualized treatment. METHODS: Plasma samples from different cities/prefectures were collected at Yunnan Provincial Hospital of Infectious Disease from January 2010 to September 2016, and those from drug-resistant individuals were genotyped using in-house assays, 88 patients were selected for the study who had been on treatment for ≥6 months (and for whom drug resistance was then measured), and each patient had at least 3 genotype resistance tests and who were enrolled to analyze mutation and evolution of HIV resistance. RESULTS: 264 Pol sequences of 88 patients were obtained. Drug resistance levels to eight drugs increased to varying degrees with prolonged treatment. Resistance to efavirenz (EFV) and etravirine (ETR) showed the highest change, comparisons of resistant changes to second and first and to third and second agents showed altered level of drug resistance were 25 and 20 cases, 28 and 18 cases, respectively. The smallest change was Lopinavir/Ritonavir (LPV/r) present 2 and 3 cases; Resistance to lamivudine (3TC) and lopinavir/ritonavir (LPV/r) was high among patients detected thrice, whereas other drugs were distributed in all resistance levels. M184 V/I (26.14%), T69S (11.36%), and T215Y/I (10.23%) mutations were the most common in nucleoside reverse transcriptase inhibitors (NRTIs), and K103 N/R/S (21.59%), V179D/E (20.45%) in Non-NRTIs (NNRTIs). Furthermore, L10 V/F/I (6.82%), A71V (4.55%), and I54V (4.55%) mutations were common in protease inhibitors (PIs). CONCLUSIONS: We found dynamic genotypic changes in HIV-1 drug-resistance in Yunnan, with prolonged treatment, and drug resistance was inevitable. However, resistance to different drugs occurred at varying times, and mutation site emergence was the main cause. These findings enhance our understanding of evolution and regulation, and are valuable for developing HIV-1 DR prevention strategies in Yunnan.

Functional Genetic Variants of PPARx03B3; and PPARα Encoding Peroxisome Proliferator-Activated Receptors and Susceptibility to Ischemic Stroke in Chinese Han Population.

BACKGROUND: PPARx03B3; and PPARα belong to a receptor family of ligand-activated transcription factors involved in the regulation of inflammation, cellular glucose uptake, protection against atherosclerosis and endothelial cell function. Through these effects, they might be involved with the ischemic stroke (IS). METHODS: One thousand two hundred ninety-six subjects from the Chinese Han Population were chosen to assess the nature of the functional polymorphisms of PPARs and any links with IS. Multivariate logistic regression analysis was used to examine the association between PPARx03B3; and PPARα genotypes and a diagnosis of IS. RESULTS: Pro/Ala carriage may be associated with the decreased risk of IS in Hans (OR 0.542, 95% CI 0.346-0.850). The 162Val allele frequency at the DNA-binding region of PPARα was extremely rare in Chinese Han population. CONCLUSIONS: PPARx03B3; 12Pro/Ala resulting in an amino acid exchange in N-terminal sequence may be an independent protective factor for IS in the Chinese Han population. However, more populations are warranted to validate our findings.

Anti-mycobacterial peptides: from human to phage.

Mycobacterium tuberculosis is the major pathogen of tuberculosis (TB). With the growing problem of M. tuberculosis resistant to conventional antibiotics, especially multi-drug resistant tuberculosis (MDR-TB) and extensively-drug resistant tuberculosis (XDR-TB), the need for new TB drugs is now more prominent than ever. Among the promising candidates for anti-TB drugs, anti-mycobacterial peptides have a few advantages, such as low immunogenicity, selective affinity to prokaryotic negatively charged cell envelopes, and diverse modes of action. In this review, we summarize the recent progress in the anti-mycobacterial peptides, highlighting the sources, effectiveness and bactericidal mechanisms of these antimicrobial peptides. Most of the current anti-mycobacterial peptides are derived either from host immune cells, bacterial extraction, or mycobacteriophages. Besides trans-membrane pore formation, which is considered to be the common bactericidal mechanism, many of the anti-mycobacterial peptides have the second non-membrane targets within mycobacteria. Additionally, some antimicrobial peptides play critical roles in innate immunity. However, a few obstacles, such as short half-life in vivo and resistance to antimicrobial peptides, need overcoming before clinical applications. Nevertheless, the multiple functions of anti-mycobacterial peptides, especially direct killing of pathogens and immune-modulators in infectious and inflammatory conditions, indicate that they are promising candidates for future drug development.

Fever with thrombocytopenia associated with a novel bunyavirus in China.

BACKGROUND: Heightened surveillance of acute febrile illness in China since 2009 has led to the identification of a severe fever with thrombocytopenia syndrome (SFTS) with an unknown cause. Infection with Anaplasma phagocytophilum has been suggested as a cause, but the pathogen has not been detected in most patients on laboratory testing. METHODS: We obtained blood samples from patients with the case definition of SFTS in six provinces in China. The blood samples were used to isolate the causal pathogen by inoculation of cell culture and for detection of viral RNA on polymerase-chain-reaction assay. The pathogen was characterized on electron microscopy and nucleic acid sequencing. We used enzyme-linked immunosorbent assay, indirect immunofluorescence assay, and neutralization testing to analyze the level of virus-specific antibody in patients' serum samples. RESULTS: We isolated a novel virus, designated SFTS bunyavirus, from patients who presented with fever, thrombocytopenia, leukocytopenia, and multiorgan dysfunction. RNA sequence analysis revealed that the virus was a newly identified member of the genus phlebovirus in the Bunyaviridae family. Electron-microscopical examination revealed virions with the morphologic characteristics of a bunyavirus. The presence of the virus was confirmed in 171 patients with SFTS from six provinces by detection of viral RNA, specific antibodies to the virus in blood, or both. Serologic assays showed a virus-specific immune response in all 35 pairs of serum samples collected from patients during the acute and convalescent phases of the illness. CONCLUSIONS: A novel phlebovirus was identified in patients with a life-threatening illness associated with fever and thrombocytopenia in China. (Funded by the China Mega-Project for Infectious Diseases and others.).

[Analysis of HIV genotypic drug resistance among pediatric HIV/AIDS cases with virological failure after free antiretroviral therapy in Yunnan province].

OBJECTIVE: To assess the prevalence and the characteristics of HIV-1 drug-resistance in pediatric HIV/AIDS cases with virological failure after free antiretroviral therapy in Yunnan Province. METHODS: The data of clinical test and laboratory detection about free antiretroviral therapy in pediatric HIV/AIDS cases from 2005 to 2012 were collected. Then the detection of HIV genotypical drug resistance was performed for the plasmas samples whose viral load were over 1 000 copies/ml after the duration of antiretroviral therapy beyond 6 months. The prevalence and the characteristics of HIV-1 drug resistance were obtained for subsequent analysis. RESULTS: A total of 73 cases suffered virological failure among 729 cases while 53 cases exhibited the resistance for antiretroviral drugs.So the resistance ratio was 72.6% (53/73) and the general resistance ratio 7.3% (53/729). The prevalent mutations associated with drug resistance were M184V/I, K103N, T215F/Y, G190A, Y181C and K101E at the frequencies of 52.1% (38/73), 30.1% (22/73), 21.9% (16/73), 20.5% (15/73), 15.1% (11/73) and 12.3% (9/73) respectively. The percentage of resistance to NVP, 3TC, EFV, D4T, AZT and ABC was 61.6% (45/73) , 54.8% (40/73) , 47.9% (35/73) , 13.7% (10/73) , 12.3% (9/73) and 5.5% (4/73) respectively. One case developed intermediate resistance to LPV/r. CONCLUSIONS: The main causes of virological failure is drug resistance.So reducing the incidence and spread of HIV drug resistance is of vital importance in modern era of resource scarcity.

Using the Molecular Transmission Networks to Analyze the Epidemic Characteristics of HIV-1 CRF08_BC in Kunming, Yunnan.

HIV-1CRF08_BC is the most prevalent epidemic subtype among heterosexual (HET) and intravenous drug users (IDUs) in Kunming, Yunnan. Using the pol region of gene sequences derived from molecular epidemiological surveys, we developed a molecular transmission network for the purpose of analyzing its epidemiological characteristics, assessing its epidemiological trends, identifying its potential transmission relationships, and developing targeted interventions. HyPhy 2.2.4 was used to calculate pairwise genetic distances between sequences; GraphPad-Prism 8.0 was employed to determine the standard genetic distance; and Cytoscope 3.7.2 was applied to visualize the network. We used the network analysis tools to investigate network characteristics and the Molecular Complex Detection (MCODE) tool to observe the growth of the network. We utilized a logistic regression model to examine the factors influencing clustering and a zero-inflated Poisson model to investigate the factors influencing potential transmission links. At the standard genetic distance threshold of 0.008, 406 out of 858 study participants were clustered in 132 dissemination networks with a total network linkage of 868, and the number of links per sequence ranged from 1 to 19. The MCODE analysis identified three significant modular clusters in the networks, with network scores ranging from 4.9 to 7. In models of logistic regression, HET, middle-aged and elderly individuals, and residents of northern and southeastern Kunming were more likely to enter the transmission network. According to the zero-inflated Poisson model, age, transmission category, sampling year, marital status, and CD4+ T level had a significant effect on the size of links. The molecular clusters in Kunming's molecular transmission network are specific and aggregate to a certain extent. HIV-1 molecular network analysis provided information on local transmission characteristics, and these findings helped to determine the priority of transmission-reduction interventions.

Subchronic Toxicity of GmDREB3 Gene Modified Wheat in the Third Generation Wistar Rats.

The aim of the current study was to evaluate the subchronic toxicity of GmDREB3 gene modified wheat in the third generation rats. SPF Wistar rats were fed with transgenic wheat diet (Gm), parental wheat diet (Jimai22) and AIN-93 rodent diet (Control), respectively, for two generations, to produce the third generation rats which were used for this study. The selected fresh weaned offspring rats (20/sex/group) were given the same diet as their parents for 13 weeks. No toxicity-related changes were observed in rats fed with Gm diet in the following respects: clinical signs, body weights, body weight gains, food consumption, food utilization rate, urinalysis, hematology, serum biochemistry and histopathology. The results from the present study demonstrated that 13 weeks consumption of Gm wheat did not cause any adverse effects in the third generation rats when compared with the corresponding Jimai22 wheat.

Two generation reproduction toxicity study of GmDREB3 gene modified wheat in Wistar rats.

To study reproductive toxicity of gene modified wheat generated by introducing DREB3 (drought response element binding protein 3) gene, Wistar rats of were allocated into 3 groups and fed with DREB3 gene modified wheat mixture diet (GM group), non-gene modified wheat mixture diet (Non-GM group) and AIN-93 diet (Control group) from parental generation (F0) to the second offspring (F2). GM wheat and Non-GM wheat, Jimai22, were both formulated into diets at a ratio of 69.55% according to AIN93 diet for rodent animals. Compared with non-GM group, no biologically related differences were observed in GM group rats with respect to reproductive performance such as fertility rate, gestation rate, mean duration, hormone level, reproductive organ pathology and developmental parameters such as body weight, body length, food consumption, neuropathy, behavior, immunotoxicity, hematology and serum chemistry. In conclusion, no adverse effect were found relevant to GM wheat in the two generation reproduction toxicity study, indicating the GM wheat is a safe alternative for its counterpart wheat regarding to reproduction toxicity.

Lower respiratory tract samples are reliable for severe acute respiratory syndrome coronavirus 2 nucleic acid diagnosis and animal model study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) continue to impact countries worldwide. At present, inadequate diagnosis and unreliable evaluation systems hinder the implementation and development of effective prevention and treatment strategies. Here, we conducted a horizontal and longitudinal study comparing the detection rates of SARS-CoV-2 nucleic acid in different types of samples collected from COVID-19 patients and SARS-CoV-2-infected monkeys. We also detected anti-SARS-CoV-2 antibodies in the above clinical and animal model samples to identify a reliable approach for the accurate diagnosis of SARS-CoV-2 infection. Results showed that, regardless of clinical symptoms, the highest detection levels of viral nucleic acid were found in sputum and tracheal brush samples, resulting in a high and stable diagnosis rate. Anti-SARS-CoV-2 immunoglobulin M (IgM) and G (IgG) antibodies were not detected in 6.90% of COVID-19 patients. Furthermore, integration of nucleic acid detection results from the various sample types did not improve the diagnosis rate. Moreover, dynamic changes in SARS-CoV-2 viral load were more obvious in sputum and tracheal brushes than in nasal and throat swabs. Thus, SARS-CoV-2 nucleic acid detection in sputum and tracheal brushes was the least affected by infection route, disease progression, and individual differences. Therefore, SARS-CoV-2 nucleic acid detection using lower respiratory tract samples alone is reliable for COVID-19 diagnosis and study.

China is implementing "Garbage Classification" action.

In recent days, garbage classification has become a hot topic in China, and Shanghai took the lead in the implementation of garbage classification legislation in China. Starting from the current situation of garbage classification in China, this study emphasizes the garbage classification in terms of law, amount, economy, management, resourcing and successful experience of garbage classification in China, so as to provide inspiration and guidance for garbage classification for other countries.

NLRP3 Inflammasome and Its Central Role in the Cardiovascular Diseases.

MATERIALS: The NLRP3 inflammasome controls the activation of the proteolytic enzyme caspase-1. Caspase-1 in turn regulates the maturation of the proinflammasome cytokines IL-1ß and IL-18, which leads to an inflammatory response. We made a mini-review on the association of regulatory mechanisms of NLRP3 inflammasome with the development of cardiovascular diseases systematically based on the recent research studies. Discussion. The inflammasome plays an indispensable role in the development of atherosclerosis, coronary heart diseases (CHD), and heart ischemia-reperfusion (I/R) injury, and NLRP3 inflammasome may become a new target for the prevention and treatment of cardiovascular diseases. Effective regulation of NLRP3 may help prevent or even treat cardiovascular diseases. CONCLUSION: This mini-review focuses on the association of regulatory mechanisms of NLRP3 inflammasome with the development of cardiovascular diseases, which may supply some important clues for future therapies and novel drug targets for cardiovascular diseases.

Prevalence of HIV-1 Drug-Resistance Genotypes Among Unique Recombinant Forms from Yunnan Province, China in 2016-2017.

To investigate the prevalence and characteristics of drug-resistance genotypes among unique recombinant forms (URFs) in HIV-1 infected people under long-term antiretroviral treatment failure from Yunnan Province. The plasma samples were collected from antiretroviral therapy (ART)-failure experienced individuals from 2016 to 2017 in Yunnan Province, China. The genotyping drug resistance of HIV-1 pol gene fragments was implemented using in-house assay. According to the analysis of RIP and MEGA 7.0, the HIV-1 strains related to URFs were screened for recombinant identification and drug resistance analysis. A total of 130 pol sequences of HIV-1 URF strains were obtained from 1,121 samples. The proportion of HIV-1 URF strains was 11.6% among the ART-failure individuals from 2016 to 2017 in Yunnan. The overall drug-resistance rate of HIV-1 URF strains was 56.9%. Meanwhile, the percentage of protease inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs), and non-nucleoside reverse transcriptase inhibitors (NNRTIs) resistance was 3.8% (5/130), 36.2% (47/130), and 53.8% (70/130), respectively. Mutations such as M184V/I (35.4%) in NRTIs and K103N/R/S/T (25.4%), V179D/E/T/Y (18.9%), G190A/E/R/S (13.8%), and Y181C (9.2%) in NNRTIs were common among the HIV-1 URF strains relative to other mutations. Factors such as male, sexual transmission pathway, and source of the year 2017 were significantly correlated with the development of HIV-1 URF drug resistance. The emergence of the multiple recombinant forms identified in Yunnan indicates active transmission networks of HIV-1 of different HIV-1 subtype/circulating recombinant forms cross-infection in this region. Therefore, it is necessary to further monitor the molecular epidemiology and drug resistance of HIV-1 in Yunnan.

Pharmacokinetics of Sodium Selenite in Rat Plasma and Tissues After Intragastric Administration.

The purpose of this research is to investigate the absorption, distribution, excretion, and pharmacokinetics of selenite in rats after intragastric administration, and thus illustrate the efficiency of selenium (Se) supplementation. After a single gavage of sodium selenite, a concentration of Se in plasma and tissues was determined by inductively coupled plasma mass spectrometry (ICP-MS) at different time points. Through fitting the data with the metabolic kinetic model, the corresponding kinetic parameters were determined for plasma and tissues, including kidney, liver, heart, muscle, and gonad. While the metabolic kinetics of sodium selenite in plasma, liver, and kidney of rats was well reflected by a two-compartment open model, that in heart and gonad was fitted to a one-compartment open model, and that in muscle was fitted to a one-compartment open model with a lag time. The results indicate that sodium selenite was absorbed by plasma and tissues quickly and was eliminated slowly after intragastric administration. Based on the results, we propose that multi-supplementation of Se with low dosage is superior to single supplementation with high dosage, in terms of avoiding selenosis.

Chronic toxicity study in Sprague-Dawley rats on transgenic rice T1c-19 with cry1C* gene.

In the present study, a novel transgenic rice line T1c-19 carrying cry1C* gene was evaluated in Sprague-Dawley (SD) rats by a 52-week feeding study, aiming at determining its unintended effects. The rice T1c-19 and its parental rice were prepared at a level of up to 60.75% in the growth diet and 66.75% in the maintenance diet, respectively. AIN-93 diet was used as a nutritional control. All the diets were nutritionally balanced. Each group, with 48 rats of both genders, was fed the corresponding diet for 52 weeks. The results of clinical signs, body weight and food consumption of the transgenic rice group were comparable to those of the parental rice group. Clinical measurements were made on weeks 13, 26 and 52, and statistical significances were observed in several hematological and serum biochemical indices between the two rice groups and were not considered as treatment-related. The terminal histopathological examination showed some spontaneous lesions in all groups with no significant difference among them. Taken together, the results of the present 52-week chronic toxicity study of transgenic rice T1c-19 exerted no unintended adverse effects on SD rats.

Cervical neoplastic lesions in relation to CD4 T-lymphocyte counts and antiretroviral therapy among women with clinical stage 1 HIV in Yunnan, China.

China lacks data demonstrating associations of cervical neoplastic lesions with CD4 T-lymphocyte (CD4 cell) counts and antiretroviral therapy (ART) among HIV-infected women, suggesting relevant investigations are needed. A total of 545 HIV-infected women were enrolled in Yunnan, China, between 2011 and 2013. CD4 cell counts and ART were measured via medical records and cervical neoplastic lesions were measured by professional pathologists. Multivariable logistic models, which treated cervical intraepithelial neoplasia (CIN) 1+ and CIN2+ as outcomes, calculated adjusted odds ratio (aOR) of CD4 cell counts and ART. Subgroup analysis treating CIN1+ as the outcome was conducted by HIV infection duration (<4 vs ≥4 years), ethnicity (Han vs non-Han), and study site (Mangshi vs Kunming). The prevalence of CIN1+ and CIN2+ was 17.4% and 7.3%, respectively. Overall, 243 (44.6%) women had CD4 cell counts ≥500 cell/µL, 187 (34.3%) used ART for less than 2 years, and 236 (43.3%) used ART for at least 2 years. We found inverse associations of CIN1+ with CD4 cell counts (≥500 compared to <500 cells/µL: aOR = 0.46, 95% CI = 0.27-0.79) and ART use (<2 years: aOR = 0.43, 95% CI = 0.21-0.87; ≥2 years: aOR = 0.54, 95% CI = 0.27-1.10). Point estimates did not change substantially for CIN2+ but aORs of ART became nonsignificant. No significant interaction was observed for HIV infection duration. We found significant interaction between CD4 cell counts and ethnicity and study site in relation to CIN1+. Our study suggests potential protective effects of high CD4 cell counts against cervical neoplastic lesions among HIV-infected women, whereas associations of ART are less consistent.

The Research Progress of Host Genes and Tuberculosis Susceptibility.

BACKGROUND/AIMS: Nucleotide diversity may affect the immune regulation of tuberculosis (TB) patients, leading to the individual susceptibility to TB. In recent years, there are a lot of researches on the association of host genetic factors and TB susceptibility which has attracted increasing attention, and the in-depth study of its mechanism is gradually clear. MATERIALS: We made a minireview on the association of many candidate genes with TB based on recent research studies systematically, such as the human leukocyte antigen (HLA) gene, the solute carrier family 11 member 1 (SLC11A1) gene system, the vitamin D receptor (VDR) gene, the mannan-binding lectin (MBL) gene, the nitric oxide synthase 2A (NOS2A) gene, the speckled 110 (SP110) gene, and the P2X7 receptor (P2X7) gene. The discovery of these candidate genes could reveal the pathogenesis of TB comprehensively and is crucial to provide scientific evidence for formulating the related measures of prevention and cure. DISCUSSION: The host genes play important roles in the development of TB, and the host genes may become new targets for the prevention and treatment of TB. Effective regulation of host genes may help prevent or even treat TB. CONCLUSION: This minireview focuses on the association of host genes with the development of TB, which may supply some clues for future therapies and novel drug targets for TB.

Epidemic Situation of Tuberculosis in Prisons in the Central Region of China.

We aimed to investigate the epidemic situation of tuberculosis (TB) in prisons in the central region of China. Tuberculosis screening was carried out in two prisons in middle China. A sum of 3,459 prisoners accepted chest X-ray examination; 40 of them were diagnosed as active TB patients. The active TB prevalence (1,156/105) was significantly higher than that of the province and China's general population (P < 0.01). As for gender, TB prevalence in men's prison (1,589/105) was higher than that in the women's prison (946/105). Nevertheless, the risk of having TB in women's prison was much higher than that in the men's prison when compared with the TB prevalence from the province (women: OR = 2.37, 95% CI: 1.34, 4.22; men: OR = 1.53, 95% CI: 0.90, 2.60) and the China's general population (women: OR = 3.30, 95% CI: 2.15, 5.09; men: OR = 2.06, 95% CI: 1.29, 3.30). In view of the severe epidemic situation of TB in prisons, integrating medical resources to establish a consummate and effective management system is necessary.

Determinants of Health Care-Seeking Delay among Tuberculosis Patients in Rural Area of Central China.

Background The prevalence of tuberculosis (TB) in low and middle-income countries is a significant public health and social concern. TB is a common infectious disease caused by the Mycobacterium tuberculosis infection, which has a widespread infection rate. Health care-seeking delay maybe one of the most important neglected risk factors for the spread of TB. Objectives The aim of this study was to understand the situation of health care-seeking delay among rural tuberculosis patients in Hubei Province, and explore its risk factors. Methods A total of 1408 rural tuberculosis patients were surveyed using a standard structured questionnaire in three cities of Hubei Province during the past two years. Results For the 1408cases of pulmonary tuberculosis, 39.70% of them were health care-seeking delayed. Logistic regressions indicate that the Han nationality, farming careers, the over 45 min walk to the township's hospital, and awareness of the national TB free treatment policy, were significantly associated with higher odds of a delay in care seeking. Conclusions The prevalence of health care-seeking delay among tuberculosis patients was high in rural areas. It is essential to take comprehensive targeted interventions to reduce care-seeking delay.

Preparation of dumbbell manganese dioxide/gelatin composites and their application in the removal of lead and cadmium ions.

The nano-sized sorbents restrict their practical application in flow-through system due to excessive pressure. In this study, dumbbell MnO2/gelatin composites were synthesized based on the protein-assisted synthesis technology. Then they were immobilized on the amino-modified polymethyl methacrylate (PMMA) plate. SEM, TEM, XRD, XPS and FT-IR were employed to study the surface properties and the adsorption mechanism of MnO2/gelatin composites. Adsorption experiments for Pb(II) and Cd(II) ions were performed to study the adsorption isotherms, kinetics, and thermodynamics as well as the influencing factors. The maximum adsorption capacities of Pb(II) and Cd(II) ions were 318.7 mg g-1 and 105.1 mg g-1 respectively. The adsorption process met the pseudo-second-order kinetic model. Subsequently, MnO2/gelatin composites modified plates were used to remove the heavy metal ions in surface water and wastewater samples. The removal efficiencies of Pb(II) ion was changed from 83% (wastewater) to 100% (surface water), when the initial concentration was 10 mg L-1. This device exhibited great application prospect in the removal of heavy metals taking advantage of its high removal efficiency, excellent stability and reusability and ease of operation.