PENGKAYAAN UNSUR YTTRIUM DAN CERIUM PADA TERAK TIMAH BANGKA: ANALISIS TERMODINAMIKA

Abstrak Pada penelitian ini, terak timah Bangka-2 (TTB-2) dilakukan serangkaian kondisi proses untuk mendapatkan hasil pengkayaan yttrium dan cerium yang optimal. Proses yang dilakukan adalah dengan melakukan pemanggangan TTB-2 pada suhu 900 °C, pelindian dengan NaOH, pelindian dengan HNO3 dan terakhir pelindian dengan H3PO4 dengan variasi konsentrasi. Analisis termodinamika dilakukan dengan perangkat lunak HSC 6.0 untuk mendapatkan Diagram Eh-pH sistem Ca-Na-H2O; Ce-Na-H2O; Y-Na-H2O; Ce-N-H2O; Y-N-H2O; Ce-P-H2O dan Y-P-H2O pada suhu 25 °C dengan tujuan melihat unsur yang terlarut ke dalam larutan NaOH, HNO3 dan H3PO4. Hasil yang didapatkan adalah kadar optimal cerium 4,39% setelah kondisi proses pelindian NaOH dan kadar yttrium mengalami peningkatan terus pada seluruh kondisi proses serta didapatkan kadar optimal 1,35% setelah dilakukan pelindian dengan HNO3 2M dan H3PO4 1,5 M. Kata Kunci: Cerium, pelindian, terak timah Bangka, unsur tanah jarang, yttrium Abstract In this analysis, the Bangka tin slag-2 (BTS-2) was carried out in a series of process conditions to obtain optimal yttrium and cerium enrichment results. The method is carried out by roasting BTS-2 at 900 °C, leaching with NaOH, leaching with HNO3, and finally leaching with H3PO4 with different concentrations. The thermodynamic analysis was performed using HSC 6.0 software to obtain the Ca-Na-H2O Eh-pH diagram system; Ce-Na-H2O; YNa-H2O; Ce-N-H2O; Y-N-H2O; Ce-P-H2O and Y-P-H2O at 25 °C to see the leached elements in NaOH, HNO3, and H3PO4 solutions. The results obtained were that the optimal cerium content was 4.39 % after the NaOH leaching phase. The yttrium content continued to increase under all process conditions, and that the optimal cerium content was 1.35 % after leaching with HNO3 2 M and H3PO4 1.5 M. Keywords: Cerium, leaching, Bangka tin slag, rare earth element, yttriu

PENGKAYAAN UNSUR YTTRIUM DAN CERIUM PADA TERAK TIMAH BANGKA: ANALISIS TERMODINAMIKA

Abstrak Pada penelitian ini, terak timah Bangka-2 (TTB-2) dilakukan serangkaian kondisi proses untuk mendapatkan hasil pengkayaan yttrium dan cerium yang optimal. Proses yang dilakukan adalah dengan melakukan pemanggangan TTB-2 pada suhu 900 °C, pelindian dengan NaOH, pelindian dengan HNO3 dan terakhir pelindian dengan H3PO4 dengan variasi konsentrasi. Analisis termodinamika dilakukan dengan perangkat lunak HSC 6.0 untuk mendapatkan Diagram Eh-pH sistem Ca-Na-H2O; Ce-Na-H2O; Y-Na-H2O; Ce-N-H2O; Y-N-H2O; Ce-P-H2O dan Y-P-H2O pada suhu 25 °C dengan tujuan melihat unsur yang terlarut ke dalam larutan NaOH, HNO3 dan H3PO4. Hasil yang didapatkan adalah kadar optimal cerium 4,39% setelah kondisi proses pelindian NaOH dan kadar yttrium mengalami peningkatan terus pada seluruh kondisi proses serta didapatkan kadar optimal 1,35% setelah dilakukan pelindian dengan HNO3 2M dan H3PO4 1,5 M. Kata Kunci: Cerium, pelindian, terak timah Bangka, unsur tanah jarang, yttrium Abstract In this analysis, the Bangka tin slag-2 (BTS-2) was carried out in a series of process conditions to obtain optimal yttrium and cerium enrichment results. The method is carried out by roasting BTS-2 at 900 °C, leaching with NaOH, leaching with HNO3, and finally leaching with H3PO4 with different concentrations. The thermodynamic analysis was performed using HSC 6.0 software to obtain the Ca-Na-H2O Eh-pH diagram system; Ce-Na-H2O; YNa-H2O; Ce-N-H2O; Y-N-H2O; Ce-P-H2O and Y-P-H2O at 25 °C to see the leached elements in NaOH, HNO3, and H3PO4 solutions. The results obtained were that the optimal cerium content was 4.39 % after the NaOH leaching phase. The yttrium content continued to increase under all process conditions, and that the optimal cerium content was 1.35 % after leaching with HNO3 2 M and H3PO4 1.5 M. Keywords: Cerium, leaching, Bangka tin slag, rare earth element, yttriu

Peningkatan Kadar Tantalum & Niobium Oksida dari Terak Timah Bangka Menggunakan Pelarut NaOH dilanjutkan dengan HNO3 dan H3PO4

Terak Timah merupakan produk samping dari proses peleburan timah yang mengandung unsur logam tantalum dan niobium. Beberapa sumber unsur tantalum dan niobium yaitu columbite, tantalite, tantalo-columbite, dll. Tantalum & niobium memiliki banyak aplikasi seperti industri pesawat terbang, elektronik dan super alloy. Penelitian ini dilakukan untuk meningkatkan kadar unsur logam tantalum dan niobium dari terak timah melalui proses pelindian asam maupun basa. Hasil penelitian menunjukan bahwa proses pemanggangan yang dilakukan tidak mengalami dekomposisi thermal, selanjutnya proses pelindian basa dengan NaOH mengakibatkan penurunan yang sangat kecil terhadap niobium yaitu dari 0,75 menjadi 0,73%, sedangkan proses pelindian dengan HNO3 dan H3PO4 memberikan peningkatan terhadap tantalum dan niobium yaitu dengan HNO3 2M menghasilkan Ta dan Nb berturut-turut 0,17 menjadi 0,85 dan 0,73 menjadi 1,49. Hal ini juga terlihat pada pelindian menggunakan campuran HNO3: H3PO4 menghasilkan peningkatan Ta dan Nb berturut-turut menjadi 0,88-0,9% dan 1,46-1,54% di setiap peningkatan variasi konsentrasi H3PO4

Two randomized trials of effect of live attenuated influenza vaccine on pneumococcal colonization

The human nasopharynx is frequently colonized by Streptococcus pneumoniae (the pneumococcus), serving as the reservoir for transmission, a state which necessarily precedes invasive pneumococcal infection. Influenza infection increases pneumococcal colonization density and dysregulates host immune responses, increasing the risk of secondary bacterial pneumonia and death

Implementation of corticosteroids in treating COVID-19 in the ISARIC WHO Clinical Characterisation Protocol UK:prospective observational cohort study

BACKGROUND: Dexamethasone was the first intervention proven to reduce mortality in patients with COVID-19 being treated in hospital. We aimed to evaluate the adoption of corticosteroids in the treatment of COVID-19 in the UK after the RECOVERY trial publication on June 16, 2020, and to identify discrepancies in care. METHODS: We did an audit of clinical implementation of corticosteroids in a prospective, observational, cohort study in 237 UK acute care hospitals between March 16, 2020, and April 14, 2021, restricted to patients aged 18 years or older with proven or high likelihood of COVID-19, who received supplementary oxygen. The primary outcome was administration of dexamethasone, prednisolone, hydrocortisone, or methylprednisolone. This study is registered with ISRCTN, ISRCTN66726260. FINDINGS: Between June 17, 2020, and April 14, 2021, 47 795 (75·2%) of 63 525 of patients on supplementary oxygen received corticosteroids, higher among patients requiring critical care than in those who received ward care (11 185 [86·6%] of 12 909 vs 36 415 [72·4%] of 50 278). Patients 50 years or older were significantly less likely to receive corticosteroids than those younger than 50 years (adjusted odds ratio 0·79 [95% CI 0·70–0·89], p=0·0001, for 70–79 years; 0·52 [0·46–0·58], p80 years), independent of patient demographics and illness severity. 84 (54·2%) of 155 pregnant women received corticosteroids. Rates of corticosteroid administration increased from 27·5% in the week before June 16, 2020, to 75–80% in January, 2021. INTERPRETATION: Implementation of corticosteroids into clinical practice in the UK for patients with COVID-19 has been successful, but not universal. Patients older than 70 years, independent of illness severity, chronic neurological disease, and dementia, were less likely to receive corticosteroids than those who were younger, as were pregnant women. This could reflect appropriate clinical decision making, but the possibility of inequitable access to life-saving care should be considered. FUNDING: UK National Institute for Health Research and UK Medical Research Council

Procalcitonin Is Not a Reliable Biomarker of Bacterial Coinfection in People With Coronavirus Disease 2019 Undergoing Microbiological Investigation at the Time of Hospital Admission

Abstract Admission procalcitonin measurements and microbiology results were available for 1040 hospitalized adults with coronavirus disease 2019 (from 48 902 included in the International Severe Acute Respiratory and Emerging Infections Consortium World Health Organization Clinical Characterisation Protocol UK study). Although procalcitonin was higher in bacterial coinfection, this was neither clinically significant (median [IQR], 0.33 [0.11–1.70] ng/mL vs 0.24 [0.10–0.90] ng/mL) nor diagnostically useful (area under the receiver operating characteristic curve, 0.56 [95% confidence interval, .51–.60]).</jats:p

Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease

We identified rare coding variants associated with Alzheimer’s disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1×10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5×10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38×10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56×10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55×10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Genetic mechanisms of critical illness in COVID-19.

Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice