Organic photocatalysis for the radical couplings of boronic acid derivatives in batch and flow.

We report an acridium-based organic photocatalyst as an efficient replacement for iridium-based photocatalysts to oxidise boronic acid derivatives by a single electron process. Furthermore, we applied the developed catalytic system to the synthesis of four active pharmaceutical ingredients (APIs). A straightforward scale up approach using continuous flow photoreactors is also reported affording gram an hour throughput

Mechanisms associated with winter intraseasonal extreme sea ice extent in the Weddell Sea

Previous studies have shown evidence of atmospheric extratropical wave trains modulating sea ice area in the Weddell and Amundsen/Bellingshausen seas on intraseasonal time-scales (20–100 d). Here we investigate mechanisms relating intraseasonal extreme sea ice extent and Ekman layer dynamics with emphasis on the Weddell Sea. This study extends from 1989 to 2013 and focuses on the winter season. Wind stress τ is calculated with winds from the Climate Forecast System reanalysis (CFSR) to evaluate momentum transfer between the atmosphere and the Ekman layer. Lag-composites of the anomalies of Ekman transport and the Ekman pumping indicate that divergence of mass in the Ekman layer and upwelling lead the occurrence of extreme sea ice contraction on intraseasonal time-scales in the Weddell Sea. Opposite conditions (i.e., convergence of the mass and downwelling) lead extreme sea ice expansion on intraseasonal time-scales. This study suggests that the Ekman pumping resulting from the anomalous wind stress on intraseasonal time-scales can transport these warmer waters to the surface contributing to sea ice melting. Additionally, high resolution sea ice fraction and ocean currents obtained from satellite and in situ data are used to investigate in detail mechanisms associated with persistent extreme sea ice expansion and contraction on intraseasonal time-scales. These case studies reveal that atmospheric circumpolar waves on intraseasonal time-scales can induce contrasting anomalies of about ±20% in sea ice concentration at the Weddell and western Antarctica Peninsula margins within less than 30 d. This study shows that extreme anomalies in sea ice may lag between 5–25 d (1–5 pentads) the ocean-atmospheric forcing on intraseasonal time-scales

Prostatic carcinomas with neuroendocrine differentiation diagnosed in needle biopsies, a morphologic study of 7 cases among 465 sequential biopsies in a tertiary cancer center

Purpose: Neuroendocrine carcinomas (NEC) of the prostate are rare, with only a few series hitherto reported. the objective of this study was to assess in a single institution the clinical and morphologic characteristics of neuroendocrine carcinomas diagnosed in needle core biopsies.Materials and Methods: the current study analyses seven cases diagnosed in needle biopsies at a large tertiary regional cancer center from Northeastern Brazil. Two pathologists reviewed specimens retrospectively, and demographic and morphologic characteristics were compared to 458 acinar tumors diagnosed in the same period.Results: There were five small cell carcinomas and two low-grade neuroendocrine carcinomas (carcinoid). NEC were associated with an acinar component in 5/7 cases and the Gleason score of the acinar component was always > 6. the number of cores involved in prostates with NEC was greater (65% compared to 24% of acinar tumors, p < 0.05). the mean PSA at diagnosis was 417.7 (range 5.7-1593, SD 218.3), compared to 100.5 (p = 0.1) of acinar tumors (range 0.3-8545, SD 22.7). Prostates harboring NEC were bigger (p < 0.001, mean volume 240 mL vs. 53 mL of acinar tumors). Treatment of NEC included palliative surgery, chemotherapy, and hormonal therapy.Conclusions: NEC of the prostate is rare and often associated with a high-grade acinar component. Prostates with NEC tend to be larger and involve a greater number of cores than acinar tumors. PSA at diagnosis does not seem to predict the presence of NE tumors in needle biopsy.Hosp Canc, Inst Canc Ceara, BR-60430230 Fortaleza, Ceara, BrazilEscola Paulista Med, BR-04023 São Paulo, BrazilEscola Paulista Med, BR-04023 São Paulo, BrazilWeb of Scienc

Comparison of 5-year progression of retinitis pigmentosa involving the posterior pole among siblings by means of SD-OCT: a retrospective study

The blockchain technology promises to transform finance, money and evengovernments. However, analyses of blockchain applicability and robustness typicallyfocus on isolated systems whose actors contribute mainly by running the consensusalgorithm. Here, we highlight the importance of considering trustless platformswithin the broader ecosystem that includes social and communication networks. Asan example, we analyse the flash-crash observed on 21st June 2017 in the Ethereumplatform and show that a major phenomenon of social coordination led to acatastrophic cascade of events across several interconnected systems. We proposethe concept of “emergent centralisation” to describe situations where a single systembecomes critically important for the functioning of the whole ecosystem, and arguethat such situations are likely to become more and more frequent in interconnectedsocio-technical systems. We anticipate that the systemic approach we propose willhave implications for future assessments of trustless systems and call for the attentionof policy-makers on the fragility of our interconnected and rapidly changing world

“Tem Química na cozinha?” – Elaboração e aplicação de uma Oficina Temática para divulgação científica

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Assessment of the genetic risks of a metallic alloy used in medical implants

The use of artificial implants provides a palliative or permanent solution for individuals who have lost some bodily function through disease, an accident or natural wear. This functional loss can be compensated for by the use of medical devices produced from special biomaterials. Titanium alloy (Ti-6Al-4V) is a well-established primary metallic biomaterial for orthopedic implants, but the toxicity of the chemical components of this alloy has become an issue of concern. In this work, we used the MTT assay and micronucleus assay to examine the cytotoxicity and genotoxicity, respectively, of an extract obtained from this alloy. The MTT assay indicated that the mitochondrial activity and cell viability of CHO-K1 cells were unaffected by exposure to the extract. However, the micronucleus assay revealed DNA damage and an increase in micronucleus frequency at all of the concentrations tested. These results show that ions released from Ti-6Al-4V alloy can cause DNA and nuclear damage and reinforce the importance of assessing the safety of metallic medical devices constructed from biomaterials