2,5-Dimethyl­hexane-2,5-diyl bis­(4-nitro­phen­yl) dicarbonate

The title structure, C22H24N2O10, contains two independent centrosymmetric mol­ecules. The only significant difference between the mol­ecules is the dihedral angle between the unique carbonate group (–O—CO2–) and the benzene ring, the values being 77.35 (8) and 66.42 (8)°. The crystal structure is stabilized by weak inter­molecular C—H⋯O hydrogen bonds

Di-tert-butyl cyclo­hex-2-ene-1,4-diyl dicarbonate

In the title mol­ecule, C16H26O6, the central cyclo­hexene ring is in a half-chair conformation. The carbonyl groups are in a trans arrangement with respect to each other and the dihedral angle between the mean planes of the carbonate groups is 10.8 (2)°

trans-Cyclo­hexane-1,4-diyl bis­(4-nitro­phen­yl) dicarbonate

In the title crystal structure, C20H18N2O10, there are two independent mol­ecules, both of which lie on crystallographic inversion centres. In one mol­ecule the 4-nitro­phenyl dicarbonate groups are substituted in equatorial (A eq) positions of the chair-form cyclo­hexane ring while in the other mol­ecule the substitution is axial (B ax). The dihedral angles between the atoms of the symmetry-unique carbonate group (O=CO2—) and benzene ring for each mol­ecule are 47.3 (1)° for A eq and 11.7 (2)° for B ax. In B ax, this facilitates the formation of a weak intra­molecular C—H⋯O hydrogen bond, while the packing is stabilized by weak inter­molecular C—H⋯O inter­actions

trans-Cyclo­hex-2-ene-1,4-diyl bis­(4-nitro­phen­yl) dicarbonate

Although the title mol­ecule, C20H16N2O10, does not possess mol­ecular inversion symmetry, it lies on a crystallographic inversion centre which imposes disorder on the central cyclo­hexene ring. In addition, the cyclo­hexene ring has non-symmetry-related disorder over two sites, with the ratio of the major and minor components being 0.54:0.46. The overall effect is to produce four disorder components for the atoms of the cyclo­hexene ring. The side chain is perfectly ordered and the dihedral angle between the atoms of the carbonate group (O=CO2—) and the benzene ring is 72.99 (6)°

Bis(4-nitro­phen­yl) 1,3-phenyl­ene­dimethyl­ene dicarbonate

In the title mol­ecule, C22H16N2O10, the dihedral angles between the benzene rings of the 4-nitro­phenyl groups and the central benzene ring are 32.7 (1) and 34.7 (1)°, while the dihedral angle between the two benzene rings of the 4-nitro­phenyl groups is 3.6 (2)°. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds link mol­ecules into centrosymmetric dimers

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

انیسویں صدی میں شاعراتِ اردو کے تذکرے— تعارف و تحقیق

Biographical Accounts (Tazkiras) are one of the most reliable sources of the information about the eminent personalities of the past. These provide a good amalgamation of social, literary and scholastic history of the given society and also become  the foundation stone of the literary criticism. The era of Tazkira writing of female Urdu poets formally starts during the end of the nineteenth century, appromixately after two centuries of tazkira writing and one century of Tazkira writing of Urdu poets in India. Tazkiras of the poetesses, not only have basic importance with respect to their nature, presentation, language and expression but also these are the only significant source of information about the Biography  and poetry of the contemporary  poetesses. This research study has presented the introduction of Tazkiras of urdu poetesses which were written in end of the nineteenth century and also effort has been made to find out that how many of these tazkiras  have been written during the period and what is style of their presentation.</p