GPM-DPR Observations on TGFs Producing Storms

Unique spaceborne measurements of the three-dimensional structure of convective clouds producing terrestrial gamma ray flashes (TGFs) were performed using both active and passive microwave sensors on board the Global Precipitation Measurement (GPM)-Core Observatory satellite, finding coherent features for nine TGF-producing storms. The delineation of cloud structure using the radar reflectivity factor shows convective cells with significant vertical development and thick layers with high ice content. Compared to other cumulonimbus clouds in the tropics, the TGFs counterparts have higher reflectivity values above 3 and 8 km altitude showing in all cases a cumulonimbus tower and the TGFs locations are very close, or coincident, to these high Z columns, where reflectivity exceeds 50dBz. Using the GPM Microwave Imager radiometer, most thunderstorms show a very strong depression of polarization corrected temperature (PCT) at channel 89GHz, indicating a strong scattering signal by ice in the upper cloud layers. At channel 166GHZ, the difference between vertical and horizontal brightness temperature signal always returns positive values, from 0.2 up to 13.7K indicating a complex structure with randomly/vertically oriented ice particles. The PCT was used to characterize the analyzed storms in terms of hydrometeor types, confirming in 7/9 cases a high likelihood of hail/graupel presence. To perform analysis on the TGFs parent flashes, radio atmospherics data from the Earth Networks Total Lightning Network lightning network were used. Waveform data indicate that all cases are intra-cloud events and TGFs typically take place during the peak of flash rate production. Finally, the analysis of the most intense event is shown

Contemporary Trends of Systemic Neoadjuvant and Adjuvant Intravesical Chemotherapy in Patients With Upper Tract Urothelial Carcinomas Undergoing Minimally Invasive or Open Radical Nephroureterectomy: Analysis of US Claims on Perioperative Outcomes and Health Care Costs

Introduction: New evidence indicates that minimally invasive surgery (MIS) (laparoscopic or robotic-assisted [LNU, RANU]) reaches oncologic equivalence compared with Open Radical Nephroureterectomy (ORNU) for high-risk upper-tract urothelial carcinoma (UTUC). Recently, European Association of Urology (EAU) Guidelines suggested implementing neoadjuvant chemotherapy (NAC) to standard treatment to improve oncologic outcomes of high-risk UTUC. We aimed (1) To explore contemporary trends of MIS for RNU in the United States and to compare perioperative outcomes and costs with that of ORNU. (2) To determine the trends of NAC and postoperative intravesical chemotherapy (PIC) administration for high-risk UTUC and to assess their contribution to perioperative outcomes and costs. Patients and methods: The Optum Clinformatics Data Mart de-identified database was queried from 2003 to 2018 to retrospectively examine patients who had undergone LNU/RANU or ORNU with or without NAC and PIC. We evaluated temporal adoption trends, complications, and health care cost analyses. We obtained descriptive statistics and utilized multivariable regression modeling to assess outcomes. Results: A total of n = 492 ORNU and n = 1618 LNU/RANU procedures were reviewed. The MIS approach was associated with a statistically significant lower risk of intraoperative complications (adjusted Odds Ratio [aOR], 0.48, 95% CI:0.24-0.96), risk of hospitalization costs (aOR: 0.62, 95% CI:0.49-0.78), and shorter hospital stay (aOR: 0.20, 95% CI:0.15-0.26) when compared to ORNU. Overall, adoption of NAC and PIC accounted for only n = 81 and n < 37 cases respectively. The implementation of NAC and higher number of cycles were associated with an increased probability of any complication rate (aOR: 2.06, 95% CI:1.26-3.36) and hospital costs (aOR: 2.12, 95% CI:1.33-3.38). Conclusion: MIS has become the approach of choice for RNU in the US. Although recommended by guidelines, neither NAC nor postoperative bladder instillation of chemotherapy has been routinely incorporated into the clinical practice of patients with UTUC

On Newtonian singularities in higher derivative gravity models

We consider the problem of Newtonian singularity in the wide class of higher derivative gravity models, including the ones which are renormalizable and superrenormalizable at the quantum level. The simplest version of the singularity-free theory has four derivatives and is pretty well-known. We argue that in all cases of local higherderivative theories, when the poles of the propagator are real and simple, the singularities disappear due to the cancelation of contributions from scalar and tensor massive modes

Stereoretentive enantioconvergent reactions

The stereoselective synthesis of chiral molecules in enantioenriched form – i.e., asymmetric synthesis – underpins many fields of pure and applied science. Enantioconvergent reactions are preeminent in contemporary asymmetric synthesis as they convert both enantiomers of a racemic starting material into a single enantioenriched product, thus avoiding the maximum 50% yield associated with resolutions. All currently known enantioconvergent processes necessitate the loss or partial-loss of the racemic substrate’s configuration, thus limiting the potential substrate scope to molecules that contain labile stereogenic units. Here we present a new approach to enantioconvergent reactions that can proceed with full retention of the racemic substrate’s configuration. This uniquely stereo-economic approach is possible if the two enantiomers of a racemic starting material are joined together to form one enantiomer of a non-meso product. Experimental validation of this concept is presented using two distinct strategies; (1) a direct unsymmetrical coupling approach and (2) a multi-component approach, which exhibits statistical-amplification of enantiopurity. Our results demonstrate that stereoretentive-enantioconvergent reactions can be achieved using a wide variety of synthetic tactics, including stoichiometric chiral reagents, chiral auxiliaries, and chiral catalysts. Thus, the established dogma that enantioconvergent reactions require substrates that contain labile stereogenic units is shown to be incorrect. We anticipate the concept of stereoretention in enantioconvergent reactions will lead to the development of novel methodologies that can utilize a hitherto unexplored range of racemic substrates