The present study investigated the effect of biochar (BC) addition on mechanical, thermal, and water resistance properties of PLA and hemp-PLA-based composites. BC was combined with variable concentration to PLA (5 wt%, 10 wt%, and 20 wt%) and hemp (30 wt%)-PLA (5 wt% and 10 wt%); then, composites were blended and injection molded. Samples were characterized by color measurements, tensile tests, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and water contact angle analysis. Experimental results showed that adding 5 wt% of BC enhanced the composite’s tensile modulus of elasticity and strength. Hence, the use of optimized loading of BC improved the mechanical strength of the composites. However, after BC addition, thermal stability slightly decreased compared with that of neat PLA due to the catalytic effect of BC particles. Moreover, the water-repelling ability decreased as BC content increased due to the specific hydrophilic characteristics of the BC used and its great porosity. 相似文献
Documenting the circulation dynamics of SARS-CoV-2 variants in different regions of the world is crucial for monitoring virus transmission worldwide and contributing to global efforts towards combating the pandemic. Tunisia has experienced several waves of COVID-19 with a significant number of infections and deaths. The present study provides genetic information on the different lineages of SARS-CoV-2 that circulated in Tunisia over 17 months. Lineages were assigned for 1359 samples using whole-genome sequencing, partial S gene sequencing and variant-specific real-time RT-PCR tests. Forty-eight different lineages of SARS-CoV-2 were identified, including variants of concern (VOCs), variants of interest (VOIs) and variants under monitoring (VUMs), particularly Alpha, Beta, Delta, A.27, Zeta and Eta. The first wave, limited to imported and import-related cases, was characterized by a small number of positive samples and lineages. During the second wave, a large number of lineages were detected; the third wave was marked by the predominance of the Alpha VOC, and the fourth wave was characterized by the predominance of the Delta VOC. This study adds new genomic data to the global context of COVID-19, particularly from the North African region, and highlights the importance of the timely molecular characterization of circulating strains. 相似文献
Seborrheic keratosis is a common benign epidermal tumor occurring in patients aged over 50 years. It is located preferentially in the trunk, head and neck. The genital location is rare. We report a case of 59 year‐old‐men presenting a seborrheic keratosis of the pubis. 相似文献
Background : Asthma is the most common chronic disease in infants. In young children, asthma still raises many questions and many points are still being debated. Aim : The aim of this study is to identifies, in asthmatic children, factors predictors of severity and persistence of symptoms. Methods: A retrospective study of asthmatic infants<3 years enrolled in the pediatric department of Sfax over a period of 5 years (2007-2011). We were interested to social and environmental factors, the allergic background, clinical severity of the disease, results of allergic skin tests, treatment and respiratory outcome.Results: We collected 180 children with a sex ratio of 2.2. Family history of atopy and exposition to passive tobacco were noted in 45 % and 52% of cases respectively. The mean age of onset of wheezing was 6.6 months. Skin tests were positives in 32% of cases. At the time of diagnosis, asthma was classified intermittent (21%), mild to moderate (55.6%) and severe (22.2%). Inhaled corticosteroids was initiated in 142 infants (78.8%). Skin tests performed in 84 patients, were positive in 32%. Factors associated with severe asthma were passive smoking, early age of onset, number of hospitalizations for exacerbation and existence of an aggravating factor.Factors predictors of persistence were an early age of onset, caesarean delivery, passive smoking and positive skin tests. Conclusion : Factors associated with persistence of asthma at the individual level remains uncertain. However, atopy and passive smoking are major indicators. 相似文献
Our objective was to investigate the prevalence and the environmental determinants of alcohol use among students in the region of Sfax in Tunisia. We carried out a cross-sectional study among 315 middle and high school students. We used the Alcohol Use Disorders Identification Test (AUDIT) to identify risky alcohol consumption, and we used the Parenting Styles and Dimensions Questionnaire (PSDQ) to assess the students’ perceptions of their parents’ parenting styles. The results show that 19.7% reported drinking alcohol at least once in their lifetime. Among them, 21% scored as dependent alcohol users, according to the AUDIT. Those who drank alcohol at least once were more likely to have parents with a permissive parenting style (p < 0.001; Cramer’s V = 0.287), and a father (p < 0.001; Cramer’s V = 0.258), a mother (p = 0.025; Cramer’s V = 0.158), or a friend (p < 0.001; Cramer’s V = 0.341) who drinks. Students perceiving their parents’ parenting style as permissive had the highest AUDIT score (p = 0.005; partial η2 = 0.132). The authoritarian style score was significantly higher for students who were current alcohol users (p = 0.028; Cohen’s d = 0.57). Our study highlights the influence of peers, family drinking, and parenting styles on alcohol use among middle and high school students. Therefore, particular attention should be given to students that are at risk of having the abovementioned environmental determinants of alcohol use. And, prevention strategies should involve parents, as well as enhanced guidance and counseling for these students.
Gigantomastia is a very rare entity of undetermined aetiology that may be due to hormonal imbalance, decreased hormonal catabolism or hypersensitivity of the target organ. It poses the problem of surgical treatment, which can be exceptionally radical of necessity. We report a case of a 32-year-old woman of whom volume and vasculocutaneous complications required a simple bilateral mastectomy to treat a recurrence of gigantomastia occurring some months after a mammoplasty. Most of the cases of gigantomastia found in the literature are associated to the pregnancy or puberty and very rare cases of spontaneous gigantomastia were listed. 相似文献
White leaf is a serious disease of sugarcane caused by phytoplasma. The disease is transmitted to the plant by the leafhopper Matsumuratettix hiroglyphicus (Matsumura). The reservoir of phytoplasma was suspected to be weeds that grow in sugarcane farming areas because they can be infected with phytoplasma and show symptoms similar to sugarcane white leaf. However in previous work we have demonstrated by RFLP and sequencing that this is not the case. Here we have reared M. hiroglyphicus through two generations by feeding them phytoplasma free sugarcane grown from tissue culture. By nested-PCR followed by sequencing, we demonstrated the presence of the phytoplasma in eggs, nymphs and adults of the first and second generations thereby showing transovarial transmission. We have also shown by in situ PCR that phytoplasmas were widely distributed throughout the body of the insect. RFLP and sequencing showed that the same phytoplasma was present in the vector and in the plant. Together, these data point to the leafhopper M. hiroglyphicus as the reservoir of phytoplasma that cause sugarcane white leaf disease. 相似文献
The study investigated the association between plasma homocysteine, folate and vitamin B12 with 5,10 methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), thymidylate synthase (TYMS 2R → 3R) and methionine synthase (MTR A2756G) polymorphisms and methotrexate (MTX) treatment and toxicity in Tunisian Rheumatoid arthritis (RA) patients.
Methods
A total of 185 patients with RA were included. Homocysteine (Hcy) was assessed by fluorescence polarization immunoassay, and folate and vitamin B12 were measured by chemiluminescence immunoassays. The genetic polymorphisms were analyzed by PCR or PCR-RFLP. Hyperhomocysteinemia (HHC) was considered for Hcy?>?15 µmol/L.
Results
MTHFR C677T polymorphism was associated with HHC in RA patients (multi-adjusted OR, 95% CI 2.18, [1.07–4.57]; p?=?0.031). No association was detected with the remaining polymorphisms. Plasma Hcy, folate, and vitamin B12 did not differ according to each polymorphism, or with MTX treatment or toxicity. However, HHC was more prevalent in patients with than those without MTX toxicity (32.7 vs. 16.7%; p?=?0.035).
Conclusions
The MTHFR 677TT genotype is an independent risk factor for HHC in Tunisians RA patients. HHC could be a useful marker of MTX toxicity in RA patients.
Uterine leiomyoma with massive lymphoid infiltration is a rare and unusual pathological finding; only 20 cases have been reported in the literature. We report a case of this unusual lesion in a 35-year-old woman who underwent a myomectomy. On gross examination, the tumor was of white color and firm consistency. Histological sections showed interlacing bundles of spindle shaped cells of low density with moderate to severe lymphocytic infiltrate associated to lymphoid follicles and few plasma cells. Immunohistochemically, the diffusely infiltrating lymphoid cells were predominantly of T cell phenotype. The interspersed spindle shaped cells were positive with alpha smooth muscle actin, desmin and h-caldesmon. The cause of this unusual lesion is not clear, but the recognition of its distinct histological features is important to avoid possible confusion with differential diagnosis including malignant lymphoma, inflammatory pseudotumor and pyomyoma. 相似文献