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Cellulose fibers (C.sub.40 and C.sub.80) were extracted from khat (Catha edulis) waste (KW) with chlorine-free process using 40% formic acid/40% acetic acid (C.sub.40 ), and 80% formic acid/80% acetic acid (C.sub.80) at the pretreatment stage, followed by further delignification and bleaching stages. Cellulose nanocrystals (CNCs.sub.40 and CNCs.sub.80) were then isolated from C.sub.40 and C.sub.80 with sulfuric acid hydrolysis, respectively. Thus, the current study aims to isolate cellulose fibers and CNCs from KW as alternative source. The KW, cellulose fibers, and CNCs were investigated for yield, chemical composition, functionality, crystallinity, morphology, and thermal stability. CNCs were also evaluated for colloidal stability, particle size, and their influence on in vitro diclofenac sodium release from gel formulations preliminarily. The FTIR spectra analysis showed the removal of most hemicellulose and lignin from the cellulose fibers. The XRD results indicated that chemical pretreatments and acid hydrolysis significantly increased the crystallinity of cellulose fibers and CNCs. The cellulose fibers and CNCs exhibited Cellulose I.sub.[beta] crystalline lattice. TEM analysis revealed formation of needle-shaped nanoscale rods (length: 101.55-162.96 nm; aspect ratio: 12.84-22.73). The hydrodynamic size, polydispersity index, and zeta potential of the CNC.sub.S ranged from 222.8-362.8 nm; 0.297-0.461, and -45.7 to -75.3 mV, respectively. CNCs.sub.40 exhibited superior properties to CNCs.sub.80 in terms of aspect ratio, and colloidal and thermal stability. Gel formulations containing high proportion of CNCs sustained diclofenac sodium release (< 50%/cm.sup.2) over 12 h. This study suggests that cellulose fibers and nanocrystals can be successfully obtained from abundant and unexploited source, KW for value-added industrial applications.

Aims There is a considerable debate on the impact of qat chewing on dental and oral health. Thereby, this study aimed at assessing the dental caries among qat chewers (QC) and non-qat chewers (NQC) who attend outpatient dental clinics, College of Dentistry, Jazan, Saudi Arabia. Materials and methods A sample of 100 QC and 100 NQC were recruited amongst those attended dental clinics, college of dentistry, Jazan University during the 2018–2019 academic year. Their dental health was assessed by three pre-calibrated male interns using DMFT index. The Care Index, Restorative Index and Treatment Index were calculated. Comparisons between both subgroups were done using independent t test. Multiple linear regression analyses were further conducted to stand on the independent determinants of the oral health among this population. Results QC were unintentionally older (36.55 ± 8.74 years) than NQC (32.96 ± 8.49 years; P  = 0.004). Fifty-six percent of QC reported brushing their teeth compared to only 35% ( P  = 0.001). NQC with university and postgraduate educational levels were more than QC. The mean Decayed [5.91 (5.16)] and DMFT [9.15 (5.87)] were higher among QC compared to NQC [3.73 (3.62) and 6.7 (4.58); P  = 0.001 and 0.001, respectively]. The other indices were not different between both subgroups. The multiple linear regression revealed that qat chewing and age, individually or together, as independent determinants for the dental decay, missing, DMFT and TI. Conclusion Qat chewing habit has a detrimental impact on dental health. It is associated with higher dental caries and missing teeth, and a lower treatment index.

In Ethiopia, malnutrition is a public health threat causing a significant burden of morbidity, mortality, and economic crisis. Simultaneously, khat consumption is alarmingly increasing among adults, yet it might contribute to the existing burden of malnutrition, where the current evidence is inconclusive. Hence, this review was to estimate the association between khat consumption and undernutrition among adults in Ethiopia. A comprehensive search for Google, Google Scholar, and PubMed, coupled with a thorough manual search of the literature, was done up to date, October 18, 2023, using relevant search terms: \"impact,\" \"effects,\" \"khat chewing,\" \"khat consumption,\" \"Ethiopia,\" \"nutritional status,\" and \"undernutrition.\" An updated PRISMA guideline was used to select relevant literature. The extracted data was summarized in narrative summaries, descriptions, and meta-analyses. The risk of bias was assessed. The results are presented in forest plots and funnel plots to assess publication bias. A pooled effect size (odds ratio) with a 95% certainty level was reported. While a total of 17 articles (n = 45,679) were included in the narrative review, only 15 articles were included in the quantitative meta-analysis. The majority of studies had a low and moderate risk of bias (based on risk of bias assessment tool), mainly due to unclear exposure assessment and high study heterogeneity. A total of 11 studies were cross-sectional studies (71%), three were comparative studies (17.4%), and three were case control studies (17.4%). There is a higher risk of publication bias as evidenced by the funnel plot. Overall, five studies were from the Oromia region, and three studies were conducted at the national level. Overall, chewing had been shown to significantly increase the risk of undernutrition by 53% (pooled OR = 1.53; 95% CI: 1.09-2.16) under a random effect model. Under the fixed effect model, higher weight was given to national-level studies with higher samples, where chewing contributed to a 12% increased risk of undernutrition (AOR = 1.12; 95% CI: 1.01-2.23). Hence, khat chewing could raise the odds of undernutrition by 12-53%. There is evidence of an association between khat chewing and an increased risk of undernutrition among adults in Ethiopia, which highlights the need for public health interventions to address the potential adverse effects of khat chewing on nutritional status.

This study sought to assess the prevalence of thrombocytopenia (TCP), underlying aetiologies of chronic liver disease, and the grading and prognostic systems for chronic liver disease (CLD) using non-invasive biomarkers: the Fibrosis index and the Model for End-Stage Liver Disease-Na (MELD-Na) Score, respectively. This was a 15-month multi-centric cross-sectional study of 105 patients with chronic liver disease (CLD). The study was conducted using Sept 2019 to Nov 2020 admission records of CLD patients from Ma'abar City in Dhamar Governorate, Yemen. A total of 63 (60%) and 42 (40%) patients were identified as thrombocytopenic and non-thrombocytopenic, respectively. The means ± SD of the MELD score and FI were 19 ± 7.302 and 4.1 ± 1.06. TCP prevalence among leukopenic and non-leukopenic patients was 89.5% and 53.5%, respectively (P = 0.004). Likewise, the prevalence of traditional-ultrasonography-diagnosed cirrhotic patients needing liver transplantation (LT) was 82.3% versus 61.3% among corresponding non-cirrhotic patients (P = 0.000). The prevalence of TCP among the participants of this study was similar to the global rate. However, the prevalence of decompensation was much higher among CLD patients than that found elsewhere, highlighting a need to improve methods for the early diagnosis of CLD in Yemen. This study also identified problems with the diagnostic work-up for non-infectious aetiologies of CLD. The findings suggest the need to improve clinician awareness about effective diagnostic strategies for these aetiologies.

The leaves of ’khat’ ( Catha edulis Forsk ), a plant widely grown in Ethiopia are chewed by local people for their stimulant action. Its branches and part of the leaves are thrown as solid waste. The objectives of this study was to characterize fuel briquette made from this waste disposed in Hawassa city, Ethiopia. First, charcoal fines were prepared from the khat branches and the leaves. The charcoal fines were then mixed with 20% of clay as a binder. It was followed by molding the mixture in a press machine to produce Branch Charcoal Briquette (BCB) and Leaves Charcoal Briquette (LCB). The experimental results showed the Carbonized Branch Briquette Charcoal (CBBC) has an average calorific values of 19,890 kJ/kg and its other performance parameters are also within the acceptable range. Hence, the city’s khat residue can be easily processed into CBBC to substitute yearly 480 ton of charcoal and reduce roughly 1,020 tons of carbon dioxide emission to the environment. The Carbonized Leaves Briquette Charcoal (CLBC) did not gave satisfactory results. Hence, it had been recommended to be studied further.

Edge-computing applications demand ultra-low-power architectures for both feature extraction and classification tasks. In this manuscript, a Keyword Spotting (KWS) system tailored for energy-constrained portable environments is proposed. A 16-channel analog filter bank is employed for audio feature extraction, followed by a digital Gated Recurrent Unit (GRU) classifier. The filter bank is behaviorally modeled, making use of second-order band-pass transfer functions, simulating the analog front-end (AFE) processing. To enable efficient deployment, the GRU classifier is trained using a Learned Step Size (LSQ) and Look-Up Table (LUT)-aware quantization method. The resulting quantized model, with 4-bit weights and 8-bit activation functions (W4A8), achieves 91.35% accuracy across 12 classes, including 10 keywords from the Google Speech Command Dataset v2 (GSCDv2), with less than 1% degradation compared to its full-precision counterpart. The model is estimated to require only 34.8 kB of memory and 62,400 multiply–accumulate (MAC) operations per inference in real-time settings. Furthermore, the robustness of the AFE against noise and analog impairments is evaluated by injecting Gaussian noise and perturbing the filter parameters (center frequency and quality factor) in the test data, respectively. The obtained results confirm a strong classification performance even under degraded circuit-level conditions, supporting the suitability of the proposed system for ultra-low-power, noise-resilient edge applications.

Substance use disorders are increasingly prevalent in sub-Saharan African countries, with evident bidirectional risk for people with severe mental illness (SMI) resulting in more severe and chronic courses. This study examines the association between common substance use, including khat and alcohol, and SMI, comparing affected individuals to age and sex-matched controls in Ethiopia. This study uses data collected as part of the NeuroGAP-Psychosis project, a large multi-country case-control genetics study. This case-control study consisted of 6,500 people with severe mental illness and age and sex-matched 6,500 controls in Ethiopia. Current substance use was defined as any use within the last three months, while current regular use was defined as at least weekly use within the previous three months. Descriptive statistics were used to determine the demographic distribution of participants, and logistic regression was used to estimate the association between substance use and severe mental illness. Most cases were men (65.8%; n = 4,276) with a mean age of 36.9 (SD = 10.3) years, while the controls were 64.7% (n = 4,204) men with a mean age of 36.2 (SD = 10.9) years. Current use of tobacco, alcohol, khat, and cannabis was 15.1%, 17.2%, 20.4% and 1.0% among cases and 6.0%, 41.5%, 12.5%, and 0.8% among controls, respectively. The adjusted odds of regular tobacco and khat use were 4.8 (95% CI: 4.0, 5.9) and 1.6 (95% CI: 1.4, 1.8) times higher in cases than in controls, respectively. However, regular use of alcohol was 0.1 (95% CI: 0.1, 0.2) times lower among cases than among controls. Tobacco and khat use were higher among cases than controls, while alcohol and cannabis use were more prevalent in controls. The high prevalence of khat use is particularly problematic in people with SMI as it adversely affects the course and outcome of mental illness. Tobacco smoking also contributes to physical health morbidity and associated premature mortality. Therefore, evidence-based screening and treatment services are warranted to mitigate the harmful health outcomes of khat use and tobacco consumption among individuals with SMI.

Background Recently, those substances deriving from the active ingredient of the Khat plant, cathinone, have been rising in popularity. Indeed, 4-methylmethcathinone (mephedrone; ‘meow meow’ and others) has been seen by some as a cheaper alternative to other classified recreational drugs. Aims We aimed here at providing a state-of-the-art review on mephedrone history and prevalence of misuse, chemistry, pharmacology, legal status, product market appearance, clinical/management and related fatalities. Methods Because of the limited evidence, some of the information here presented has been obtained from user reports/drug user-orientated web sites. The most common routes for mephedrone recreational use include insufflation and oral ingestion. It elicits stimulant and empathogenic effects similar to amphetamine, methylamphetamine, cocaine and MDMA. Due to its sympathomimetic actions, mephedrone may be associated with a number of both physical and psychopathological side effects. Recent preliminary analysis of recent UK data carried out in 48 related cases have provided positive results for the presence of mephedrone at postmortem. Discussion and Conclusions Within the UK, diffusion of mephedrone may have been associated with an unprecedented combination of a particularly aggressive online marketing policy and a decreasing availability/purity of both ecstasy and cocaine. Mephedrone has been recently classified in both the UK and in a number of other countries as a measure to control its availability. Following this, a few other research psychoactives have recently entered the online market as yet unregulated substances that may substitute for mephedrone. Only international collaborative efforts may be able to tackle the phenomenon of the regular offer of novel psychoactive drugs.

Khat is a plant that is used for its amphetamine-like stimulant properties. However, although khat is very popular in Eastern Africa, Arabian Peninsula, and the Middle East, there is still a lack of studies researching the possible neurobehavioral impairment derived from khat use. A systematic review was conducted to identify studies that assessed the effects of khat use on neurobehavioral functions. MedLine, Scopus, Cochrane, Web of Science and Open Grey literature were searched for relevant publications from inception to December 2020. Search terms included (a) khat and (b) several cognitive domains. References from relevant publications and grey literature were also reviewed to identify additional citations for inclusion. A total of 142 articles were reviewed, 14 of which met the inclusion criteria (nine human and five rodent studies). Available human studies suggest that long term khat use is associated with significant deficits in several cognitive domains, including learning, motor speed/coordination, set-shifting/response inhibition functions, cognitive flexibility, short term/working memory, and conflict resolution. In addition, rodent studies indicated daily administration of khat extract resulted in dose-related impairments in behavior such as motor hyperactivity and decreased cognition, mainly learning and memory. The findings presented in this review indicates that long-term khat use may be contributing to an impairment of neurobehavioral functions. However, gaps in literature were detected that future studies could potentially address to better understand the health consequences of khat use.

Khat chewing has become a common practice among university students in developing countries like Ethiopia. It has a potential effect on physical, mental, social and cognitive aspects of student functioning. In Ethiopia, study findings regarding the prevalence of khat chewing were highly dispersed and inconsistent. Therefore, this systematic review and meta-analysis estimates the pooled prevalence of khat chewing and its predictors among Ethiopian university students. A systematic review and meta-analysis was conducted to assess the prevalence and predictors of khat chewing among university students in Ethiopia. We searched literature from the databases of PubMed, Google Scholar, Science Direct, and the Cochrane Library. A total of 24 Ethiopian studies reporting the prevalence of khat chewing among university students were included. Data were extracted using a standardized data extraction format prepared in Microsoft Excel and the analysis was done using STATA 14 statistical software. To assess heterogeneity, the Cochrane Q test statistics and I2 test were used. Since the included studies exhibit high heterogeneity, a random effect meta-analysis model was computed to estimate the pooled prevalence of khat chewing. Moreover, the association between predictor variables, and khat chewing practice were examined. The meta-analysis of 24 studies revealed that the pooled prevalence of khat chewing among university students in Ethiopia was 23.22% (95% CI: 19.5, 27.0). In the subgroup analysis, the highest prevalence was observed in Oromia region (31.6%; 95CI: 21.2, 41.9) whereas the lowest prevalence was observed in Amhara region (18.1%; 95%CI: 12.4, 23.8). Being male OR: 2.76 (95% CI 1.64, 4.63), family khat chewing practice OR: 2.91 (95% CI 1.06, 7.98), friend khat chewing habit OR: 4.74 (95% CI 3.48, 13.06), alcohol drinking OR: 7.06 (95% CI 5.65, 8.82) and cigarette smoking habit OR: 15.11 (95% CI 8.96, 25.51) were found to be predictors of khat chewing. The study found that the prevalence of khat chewing among university students was quite common, with slightly more than 1 in 5 students engaging in the use of this substance. Being male, family khat chewing practice, friend's khat chewing habit, alcohol drinking, and cigarette smoking were found to be predictors of khat chewing practice among university students.