Chitosan/mangiferin particles for Cr(VI) reduction and removal

AbstractIn this work, chitosan/mangiferin particles (CMP) were prepared by spray-drying technique and characterized by SEM, DLS, FTIR, HPLC–UV and adsorption studies to investigate a possible application as a preventive material in cases of human and animal contamination with Cr(VI). CMP presented sizes ranging from nano to micrometers. Chitosan and mangiferin (MA) presence in the powder was confirmed by FTIR and MA quantification (136μg/mg) was performed using a calibration curve prepared by HPLC–UV. Adsorption capacity of Cr(VI) onto CMP was compared with chitosan and investigated in a batch system by considering the effects of various parameters like contact time, initial concentration of adsorbent and pH. Cr(VI) removal is pH dependent and it was found to be maximum at pH 5.0. The results showed that CMP has a potential application as a preventive material in cases of human or animal contamination with Cr(VI)

Continuous population-level monitoring of SARS-CoV-2 seroprevalence in a large European metropolitan region.

Effective public health measures against SARS-CoV-2 require granular knowledge of population-level immune responses. We developed a Tripartite Automated Blood Immunoassay (TRABI) to assess the IgG response against three SARS-CoV-2 proteins. We used TRABI for continuous seromonitoring of hospital patients and blood donors (n = 72'250) in the canton of Zurich from December 2019 to December 2020 (pre-vaccine period). We found that antibodies waned with a half-life of 75 days, whereas the cumulative incidence rose from 2.3% in June 2020 to 12.2% in mid-December 2020. A follow-up health survey indicated that about 10% of patients infected with wildtype SARS-CoV-2 sustained some symptoms at least twelve months post COVID-19. Crucially, we found no evidence of a difference in long-term complications between those whose infection was symptomatic and those with asymptomatic acute infection. The cohort of asymptomatic SARS-CoV-2-infected subjects represents a resource for the study of chronic and possibly unexpected sequelae

Integral trees homeomorphic to a double star

Trees with two nonadjacent vertices of degree larger than two are not integral. This settles a question by Watanabe & Schwenk (1979)

Cytopathological Test Performed During Colonoscopy In The Diagnosis Of Colorectal Stenosis [exame Citopatológico Realizado Durante Colonoscopia No Diagnóstico Das Estenoses Colorretais.]

The etiological diagnosis for the colorectal strictures can be very difficult. With the colonoscopy, it was possible to obtain samples with direct vision of the lesion. Consequently, the cytologic efficiency improved, with similar or even better results than histopathology. In the present study (107 patients) it was used the cytopathology performed during colonoscopy. After a specimen was obtained, it was smeared on glass slide, fixed in 95% alcohol, stained by HE, and examined microscopically, with conclusions during the procedure. The results were compared and further correlated to the histopathology of surgical specimen or based on clinical follow-up in those case not submitted to operation. The results showed a striking degree of correlation between both exams. For the cytopathology there were no inconclusive results, false-negative were less frequent than with histopathology, and only one case of false-positive (rectal villus adenoma) was observed. Considering the type, localization and perviousness of the lesion, similar conclusions were drawn, and did not affect the results, except that there were more false-negatives in both exams when the lesions were impervious. The cytopathological and histopathological studies were both highly sensitive and specific for the diagnosis of carcinoma. In conclusion, cytopathology performed during colonoscopy is safe and efficient in the study of colorectal strictures, which contributes to improve the orientation of these patients.29380853esi,Palantir Solutions,Society of Petroleum Evaluation Engineers (SPEE

Behavior pattern of beef heifers supplemented with different energy sources on oat and ryegrass pasture

The objective of this study was to evaluate behavior patterns of heifers grazing on black oat (Avena strigosa Schreb.) and ryegrass (Lolium multiflorum Lam.), fed supplementation with brown rice meal and/or protected fat. A total of 28 Charolais × Nellore crossbred heifers at average initial age of 18 months and with initial live weight of 274.9±4.97 kg were used in the experiment. Animals were kept in oat + ryegrass pastures and distributed in the following treatments: no supplementation; Megalac (MEG): protected fat supplementation; supplementation with brown rice meal (BRM); and supplementation with BRM + MEG. The neutral detergent fiber (NDF) intake of pasture either in kg or in percentage of live weight was not changed by supply of supplement, but increased linearly (0.045 kg per day) over grazing periods. Supplementation with BRM and BRM + MEG reduced grazing time, 49.63%, in relation to non-supplemented animals and animals supplemented with MEG, 63.13%. Feeding seasons per minute increased over the experimental period with reduction in time spent in each feeding station. The number of bites per feeding station decreased linearly, with a variation of 34.48% in the late grazing period. Heifers supplemented with BRM and BRM + MEG require less time for grazing and increase their idle time, with no modification in displacement patterns within the paddocks and pasture ingestion. Grazing and idle time does not change in the distinct periods of pasture use, but rumination time increases with days of pasture use and with increase in NDF intake