Regioselective Synthesis of 3-Hydroxy-4,5-alkyl-Substituted Pyridines Using 1,3-Enynes as Alkynes Surrogates

The poor regioselectivity of the [4 + 2] cycloaddition of 3-azetidinones with internal alkynes bearing two alkyl substituents via nickel-catalyzed carbon–carbon activation is addressed using 1,3-enynes as substrates. The judicious choice of substitution on the enyne enables complementary access to each regioisomer of 3-hydroxy-4,5-alkyl-substituted pyridines, which are important building blocks in medicinal chemistry endeavors

Rapidly progressive post-transplant lymphoproliferative disease following withdrawal of sirolimus

Sirolimus, a potent inhibitor of B- and T-cell activation, is a commonly used immunosuppressant after renal transplantation. Withdrawal of sirolimus from the immunosuppression regimen may reduce B-cell surveillance. We present a case of rapidly progressive central nervous system (CNS) polymorphic Epstein-Barr virus (EBV)-related post-transplant lymphoproliferative disorder following the withdrawal of sirolimus

Tenofovir alafenamide: An initial experience at Groote Schuur Hospital, Cape Town, South Africa

Background. Hepatitis B virus (HBV) remains endemic in South Africa (SA), with a concomitantly high prevalence of HIV co-infection. Chronic kidney disease in these subpopulations also has a high prevalence. Tenofovir is an important component of management, but the associated risk of nephrotoxicity makes dosing a challenge in patients with impaired kidney function. A new formulation, tenofovir alafenamide fumarate (TAF), with a more favourable renal toxicity profile, is now available.Objectives. To evaluate our initial experience of TAF use at Groote Schuur Hospital, Cape Town.Methods. We retrospectively reviewed patients with HBV mono-infection and HIV-HBV co-infection who were initiated on TAF since 2018. We recorded all relevant demographic, serological, virological and biochemical data from patient records. Adherence was documented by pill collection at the pharmacy.Results. A total of 26 patients were included in the evaluation, median (interquartile range (IQR)) age 48 (39 - 51) years, 73% (n=19) male, 27% (n=7) hepatitis B e-antigen-positive, and 46% (n=12) HIV co-infected. The median (IQR) duration of treatment with TAF was 13 (9 - 15) months. The median (IQR) baseline creatinine level was 180 (130 - 227) µmol/L, with significant improvement at 12 months, 122 (94 - 143) µmol/L; p=0.017. Reflecting this change, the estimated glomerular filtration rate improved significantly from baseline to month 12 (42 (25 - 52) and 51 (48 - 68) mL/min/1.73 m2, respectively; p=0.023). Similarly, serum alanine aminotransferase (ALT) normalised from a baseline of 33 (18 - 52) to 18 (15 - 24) U/L at month 12 (p=0.012). HBV DNA viral load also declined, from a baseline of log10 4.04 (2.5 - 7.8) IU/mL to a median of <log10 1.3 IU/mL at month 12. HIV viral load was less than the lower level of quantification at months 6 and 12.Conclusions. TAF was well tolerated, with stable and significantly improving kidney function throughout a 12-month follow-up period. Serum ALT normalised, mirrored by declining HBV viral load. HIV viral load remained undetectable at 6 and 12 months

Results from Beam Commissioning of an SRF Plug Gun Cavity Photoinjector

Superconducting rf photo electron injectors SRF photoinjectors hold the promise to deliver high brightness, high average current electron beams for future light sources or other applications demanding continuous wave operation of an electron injector. This paper discusses results from beam commissioning of a hybrid SRF photoinjector based on a Pb coated plug and a Nb rf gun cavity for beam energies up to 2.5MeV at Helmholtz Zentrum Berlin HZB . Emittance measurements and transverse phase space characterization with solenoid scan and slitmask methods will be presente

RESULTS FROM BEAM COMMISSIONG OF AN SRF PLUG-GUN CAVITY PHOTOINJECTOR

Abstract Superconducting rf photo-electron injectors (SRF photoinjectors) hold the promise to deliver high brightness, high average current electron beams for future light sources or other applications demanding continuous wave operation of an electron injector. This paper discusses results from beam commissioning of a hybrid SRF photoinjector based on a Pb coated plug and a Nb rf gun cavity for beam energies up to 2.5 MeV at Helmholtz-Zentrum Berlin (HZB). Emittance measurements and transverse phase space characterization with solenoid-scan and slitmask methods will be presented. MOTIVATIO

Clinical experience with severe acute respiratory syndrome Coronavirus 2-related illness in children : hospital experience in Cape Town, South Africa

CITATION: van der Zalm, M. M. et al. 2021. Clinical Experience With Severe Acute Respiratory Syndrome Coronavirus 2-Related Illness in Children: Hospital Experience in Cape Town, South Africa. Clinical infectious diseases, 72(12):e938–e944. doi:10.1093/cid/ciaa1666The original publication is available at https://academic.oup.com/cid/Background: Children seem relatively protected from serious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease, but little is known about children living in settings with high tuberculosis and human immunodeficiency virus (HIV) burden. This study reflects clinical data on South African children with SARS-CoV-2. Methods: We collected clinical data of children aged <13 years with laboratory-confirmed SARS-CoV-2 presenting to Tygerberg Hospital, Cape Town, between 17 April and 24 July 2020. Results: One hundred fifty-nine children (median age, 48.0 months [interquartile range {IQR}, 12.0-106.0 months]) were included. Hospitalized children (n = 62), with a median age of 13.5 months (IQR, 1.8-43.5 months) were younger than children not admitted (n = 97; median age, 81.0 months [IQR, 34.5-120.5 months]; P < .01.). Thirty-three of 159 (20.8%) children had preexisting medical conditions. Fifty-one of 62 (82.3%) hospitalized children were symptomatic; lower respiratory tract infection was diagnosed in 21 of 51 (41.2%) children, and in 11 of 16 (68.8%) children <3 months of age. Respiratory support was required in 25 of 51 (49.0%) children; 13 of these (52.0%) were <3 months of age. One child was HIV infected and 11 of 51 (21.2%) were HIV exposed but uninfected, and 7 of 51 (13.7%) children had a recent or new diagnosis of tuberculosis. Conclusions: Children <1 year of age hospitalized with SARS-CoV-2 in Cape Town frequently required respiratory support. Access to oxygen may be limited in some low- and middle-income countries, which could potentially drive morbidity and mortality. HIV infection was uncommon but a relationship between HIV exposure, tuberculosis, and SARS-CoV-2 should be explored.https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciac266/6591403Publishers versio

COMPRESSION OF ENVELOPE SOLITONS IN NONLINEAR ELECTRICAL LINES

La propagation des solitons enveloppe dans les lignes non linéaires de transmission électrique et de transmission Josephson est étudiée sous l'aspect théorique et en simulation numérique. Dans l'approximation des milieux continus et la limite des faibles amplitudes, les équations caractéristiques de ces lignes se ramènent à l'équation NLS . La solution "à deux solitons enveloppe" se propage parfaitement dans les lignes considérées avec des phénoménes de récurrence et de compression d'enveloppe. Ceci est observé également pour des profils d'excitation non solution de NLS, ce qui est d'un grand intérêt pour les applications pratiques.We study theoretically and numerically the properties of envelope solitons in a nonlinear electrical transmission line and in a Josephson transmission line, in a small amplitude limit. In the continuum limit and weak amplitude limit, we reduce the characteristic equations of these systems to NLS equation and we study "the two solitons envelope" solutions which propagate with recurrence phenomena along the two types of lines. Compression of envelope is observed for the academic solutions but we show that, even with a non-academic profile, the full width at half maximum is reduced, which is of a great interest for practical applications