Solid-liquid separation of digestate from biogas plants: A systematic review of the techniques' performance.

Digestate processing is a strategy to improve the management of digestate from biogas plants. Solid-liquid separation is usually the primary step and can be followed by advanced treatments of the fractions. The knowledge about the performance of the separators and the quality of the fractions is scattered because of many available techniques and large variability in digestate characteristics. We performed a systematic review and found 175 observations of full-scale solid-liquid separation of digestate. We identified 4 separator groups, 4 digestate classes based on substrate, and distinguished whether chemical conditioners were used. We confirmed the hypothesis that the dominant substrate can affect the efficiency of the digestate separation. Furthermore, the results showed that centrifuges separated significantly more dry matter and total P than screw presses. Use of chemical conditioners in combination with a centrifuge lowered the dry matter concentration in the liquid fraction by 30%. Screw presses consumed 4.5 times less energy than centrifuges and delivered 3.3 tonne ammonium N in the liquid fraction and 0.3 tonne total P in the solid fraction using 1 MWh. The results can provide data for systems analyses of biogas solutions and can support practitioners when choosing among full-scale separator techniques depending on the digestate type. In a broader perspective, this work contributes to the continuous improvement of biogas plants operations and to their role as nutrients recovery sites.

Development and Verification of a Traditional Chinese Medicine Diagnostic Scale for Type 2 Diabetes Mellitus with Turbid-Toxin Accumulation Syndrome / 中医杂志

To develop a traditional Chinese medicine （TCM） diagnostic scale for type 2 diabetes mellitus with turbid-toxin accumulation syndrome and to validate the performance of the scale. A candidate pool was established through literature review and expert consultation， and a clinical case information collection form was developed accordingly. Patients with type 2 diabetes mellitus admitted to the First Teaching Hospital of Tianjin University of Traditional Chinese Medicine from July 2021 to January 2022 were investigated， and 312 valid clinical case information collection forms were obtained， which were randomly divided into 235 cases in the study group and 77 cases in the validation group. Four statistical methods， namely， differentiation analysis， Cronbach's coefficient， correlation coefficient， and stepwise regression， were used to screen out the candidate items， and Logistic regression analysis and factor analysis were used to assign weights to the items， and the final diagnostic model was determined by the receiver operating characteristic （ROC） curve， and the diagnostic thresholds were calculated for the Yoden index. The final TCM diagnostic scale for type 2 diabetes mellitus was composed of 8 items： turbid dirt coating （with a weight value of 23， the same below）， sticky stools （16）， fullness in the epigastrium and abdomen （12）， dark complexion （12）， irritability （11）， brown spots on the skin （11）， heaviness of head （10）， and chest stuffiness （5）， and the degree score was 0， 0.5， 1.0， and 1.5 points corresponding to no， mild， moderate and severe symptoms， respectively. The total score was the sum of the degree score multiplied by the weighted value of each item， and when the total score reached 33 points， it is diagnosed as the turbid-toxin accumulation syndrome. The established scale was tested and evaluated in the study group and the validation group， and the results showed that the sensitivity of the study group and the validation group was 89.38% and 89.47%， with the specificity of 95.90% and 89.74%， the Yoden index of 0.85 and 0.79， the positive predictive value of 95.28% and 89.47%， the negative predictive value of 90.70% and 89.74%， the diagnostic advantage ratios of 198.18 and 72.67， and the Kappa values of 0.86 and 0.79， which indicated that the TCM diagnostic scale for turbid-toxin accumulation syndrome of type 2 diabetes mellitus showed good diagnostic ability.

One size does not fit all: psychometric properties of the Shona Symptom Questionnaire (SSQ) among adolescents and young adults in Zimbabwe.

BACKGROUND: Depression is a major contributor to the global burden of disease. Onset commonly occurs during the adolescent period. Understanding how depression tools are functioning among adolescents has been relatively overlooked. METHODS: Using cross-sectional survey data among a sample of 2768 adolescents (aged 15-19) and 2027 young adults (aged 20-24) living in Zimbabwe this paper calibrated the Shona Symptom Questionnaire (SSQ) against the Self Report Questionnaire (SRQ-20) and examined the performance indices of the SSQ based on various cut points for classification. Using a multivariate logistic regression model we isolated particular characteristics to test their association with the odds of being misclassified as non-depressed by the SSQ. RESULTS: A modified cut point of five or more substantially increases the depression estimates for both age groups. The prevalence of depression increased from 3.5% to 13.2% among adolescents and from 5.1% to 16.2% among young adults based on these revisions. Adolescents who were orphaned or ever had sex had significantly a greater odd of being misclassified. When retested using the modified cut point of five or greater, associations with misclassification disappeared. LIMITATIONS: Scales were not administered separately or in their entirety but rather overlapping items were only asked once, utilizing exclusively SRQ-20 phrasing rather than the culturally-emic language in the SSQ. CONCLUSIONS: Not all depression scales are appropriate for use among adolescents given their unique developmental stage. An alternative cut point for depression classification could improve detection of depression among Zimbabwean adolescents.

Influence of gender on psychomotor vigilance task performance by adolescents

During adolescence, the sleep phase delay associated with early school times increases daytime sleepiness and reduces psychomotor performance. Some studies have shown an effect of gender on psychomotor performance in adults and children. Males present faster reaction times (RT) compared with females. The aim of the present study was to evaluate the influence of gender on Palm psychomotor vigilance task (PVT) performance in adolescents. Thirty-four adolescents (19 girls, 13 to 16 years old) attending morning school classes of a public school in Curitiba, PR, Brazil, participated in the study. Sleep patterns were measured using actigraphy and sleepiness data were accessed with the Karolinska Sleepiness Scale (KSS). KSS and PVT measurements were collected at two times in the morning (8:00 and 11:00 h). The data were compared using one-way ANOVA, considering gender as a factor. ANOVA indicated that gender did not affect sleep patterns and subjective somnolence; however, a statistically significant effect of gender was detected for PVT performance. Boys presented faster RT (RT-PVT1: 345.51 ms, F = 6.08, P < 0.05; RT-PVT2: 343.30 ms, F = 6.35, P < 0.05) and fewer lapses (lapses-PVT1: 8.71, F = 4.45, P < 0.05; lapses-PVT2: 7.82, F = 7.06, P < 0.05) compared with girls (RT-PVT1: 402.96; RT-PVT2: 415.70; lapses-PVT1: 16.33; lapses-PVT2: 17.80). These results showed that this effect of gender, already reported in adults and children, is also observed in adolescents. The influence of gender should be taken into account in studies that use Palm PVT to evaluate psychomotor performance in this age range.