bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unexpected Coordination Modes of Bisphosphoramides with Lanthanum(III) and Thorium(IV) Salts: Synthesis, Structural Characterization, Stability, and Extraction Studies
Authors: Goud E. Veerashekhar , Vijai Anand A. S. , Pallepogu Raghavaiah , Brahmmananda Rao C. V. S. , Nagarajan Sivaraman , Sivaramakrishna Akella 
Published: March 2021

AbstractA series of bisphosphoramides of the type R2P(O)NHCH2CH2NHP(O)R2 (L) (where R=n‐butyl, n‐hexyl, n‐octyl, ethoxy, phenyl) is synthesized in two‐steps by Atherton‐Todd reaction of ethylenediamine and H‐phosphonate derived from the reaction of diethylphosphite and the Grignard reagent. These ligands were employed in the preparation of La(III) and Th(IV)complexes of the general type [LaCl3(L)2]n and [Th(NO3)4Th(IV)2]. Notably, La(III) complexes of bisphosphoramides are found as infinite coordination polymers with bridging phosphine oxide ligands in an intermolecular fashion. In contrast, Th(IV) complexes are formed with two chelating bisphosphoramide ligands around the metal center intramolecularly. All these ligands and the corresponding metal complexes are characterized by spectroscopic and analytical data. The single‐crystal X‐ray analyses of lanthanum and thorium complexes each confirm the coordination modes. Further, these ligands were evaluated to check the extraction behavior with Am(III), U(VI), Th(IV), and Pu(IV) as a function of nitric acid concentration.
COVID‐19 into Chemical Science Perspective: Chemical Preventive Measures and Drug Development
Authors: Adhikari Bimalendu , Sahu Nihar 
Published: March 2021

AbstractCOVID‐19 facts and literature are discussed into chemical science intuition highlighting the direct role of chemistry to the ongoing global pandemic by covering structural identification of the virus, chemical preventive measures and development of drugs. We reviewed the four most promising repurposed drugs which are presently being investigated in mass clinical trials on COVID‐19 infected persons and synthetic routes of these drugs with their recent advancement. Chemical preventive measures such as soap water, hand sanitizer and disinfectant are the only available options in the arsenal to fight against COVID‐19, till an effective medicine or vaccine will be made available. As such the present review will focus on the mode of action of the major chemical preventives.
Visible Light Driven VO2/g‐C3N4 Z‐Scheme Composite Photocatalysts for Selective Oxidation of DL‐1‐Phenylethyl Alcohol under Vis‐LEDs Irradiation and Aerobic Oxidation
Authors: Ma Xiuqiang , Huo Xiangyu , Hao Kun , Song Liang , Yu Qing , Liu Tong , Wang Zhongwei 
Published: March 2021

AbstractA novel VO2/g‐C3N4 Z‐Scheme type heterostructure composite photocatalyst was fabricated by the ultrasonic‐assisted method. The newly synthesized photocatalyst has been systematically and comprehensively characterized and analyzed. Through the selective oxidation of DL‐1‐Phenylethyl alcohol under Vis‐LED irradiation and aerobic oxidation, the photocatalytic performance of VO2/g‐C3N4 photocatalyst was investigated. The results showed that the prepared VO2/g‐C3N4 nanocomposites exhibited excellent photocatalytic oxidation performance. Among them, the highest turnover frequency (TOF) was 0.42 mmol (DL‐1‐Phenylethyl alcohol)⋅mmol−1 (catalyst)⋅h−1, which was 5 times higher than the TOF of the original g‐C3N4. The effects of different wavelengths of LED monochromatic light, the composite ratio of VO2 and g‐C3N4, the reaction time, and the different benzyl alcohol substrates were studied. Also, catalyst life test was completed. Furthermore, a persuasive mechanism of photocatalytic selective oxidation of DL‐1‐Phenylethyl alcohol on VO2/g‐C3N4 photocatalyst was proposed through EPR and radical trapping experiments.
Assembly of SBA‐15 Derived Hybrid Heterogeneous Catalysts for Liquid Phase Cyclopentene Epoxidation
Authors: Niu Qingtao , Liu Guodong , Lv Zhiguo , Si Chongdian , Jin Manman 
Published: March 2021

AbstractThree two‐dimensional SBA‐15‐based hybrid materials, SBA‐15‐ImCl‐PF6, SBA‐15‐NH(PO3H2), and SBA‐15‐N+, were synthesized employing a post‐synthetic functionalization strategy, and peroxo‐W and PW species were successfully immobilized on the surface of the corresponding organic moieties‐modified SBA‐15 via electrostatic interaction or covalent linking. The TEM and XRD results presented that the structure and morphology of SBA‐15 were maintained after multiple transformations. The final catalysts SBA‐15‐ImCl‐PF6‐W, SBA‐15‐NH(PO3H2)‐W, and SBA‐15‐N+(PW4O24)3− all showed considerable activity for the epoxidation of cyclopentene to cyclopentene oxide using H2O2 as the oxygen source without any co‐solvent. It was noteworthy that SBA‐15‐ImCl‐PF6‐W catalyst with increased hydrophobicity via altering counteranions of imisazolium ions exhibited excellent cyclopentene oxide selectivity (99 %), but a good cycle performance (10 times) was achieved via SBA‐15‐NH(PO3H2)‐W owing robust covalent bonds. Besides, the use of a low dose of heterogeneous catalyst (W=20 μmol) and a green oxidant of H2O2, along with the absence of co‐solvent or other additives make cyclopentene epoxidation reaction an environmenttally benign chemical process.
Hydrogen Spillover Facilitating Reduction of Surface Oxygen Species on Porous Carbon
Authors: Zheng Zhuangzhuang , Chen Mingming , Zheng Xuewen , Liu Kunlin , Yang Ting , Zhang Jizong 
Published: March 2021

AbstractSurface oxygen‐containing functional groups of porous carbon have great influence on its various properties, including the catalytic performance, chemical stability, and adsorption capacity. In this paper, a catalytic hydrogen spillover method was proposed to prepare porous carbons with low oxygen content in 7 vol % H2/Ar atmosphere. Pt/C was used as the catalyst. Petroleum coke‐based porous carbon was adopted as the model material to study hydrogen spillover reduction effect within the temperature range of 500–700 °C. XRD, Raman and XPS were used to characterize the microstructures and surface chemical composition of prepared materials. Compared with H2 reduction, hydrogen spillover reduction can further increase graphitic degree of porous carbon without destroying the morphology and pore structure, and can reduce the contents of surface oxygen‐containing groups of porous carbon more effectively. And among different kinds of oxygen‐containing groups, the more reactive hydrogen atoms dissociated by Pt/C catalyst have the best reduction effect on C−O species.
Posterior compartment symptoms in primiparous women 1 year after non-assisted vaginal deliveries: a Swedish cohort study
Authors: Rotstein Emilia , Åhlund Susanne , Lindgren Helena , Lindén Hirschberg Angelica , Rådestad Ingela , Tegerstedt Gunilla 
Published: March 2021

Abstract
Introduction and hypothesis
This is a prospective cohort follow-up study based on the hypothesis that primiparous women with non-assisted vaginal deliveries and a second-degree perineal tear have more posterior compartment symptoms 1 year after delivery than those with no or first-degree tears.

Methods
A follow-up questionnaire, including validated questions on pelvic floor dysfunction, was completed 1 year postpartum by 410 healthy primiparas, delivered without instrumental assistance at two maternity wards in Stockholm between 2013 and 2015. Main outcome measures were posterior compartment symptoms in women with second-degree perineal tears compared with women with no or only minor tears.

Results
Of 410 women, 20.9% had no or only minor tears, 75.4% had a second-degree tear, and 3.7% had a more severe tear. Of women presenting with second-degree tears, 18.9% had bowel-emptying difficulties compared with 20.0% of women with minor tears. Furthermore, almost 3% of them with second-degree tears complained of faecal incontinence (FI) of formed stool, 7.2% of FI of loose stool compared with 1.2% and 3.5% respectively in women with no or only minor tears.

Conclusions
Symptomatic pelvic floor dysfunction is common among primiparous women within 1 year following uncomplicated vaginal delivery, and there are no significant differences between second-degree perineal tears and minor tears. These symptoms should be addressed in all women after delivery to improve pelvic floor dysfunction and quality of life.
On the Cycle Augmentation Problem: Hardness and Approximation Algorithms
Authors: Gálvez Waldo , Grandoni Fabrizio , Jabal Ameli Afrouz , Sornat Krzysztof 
Published: March 2021

AbstractIn the k-Connectivity Augmentation Problem we are given a k-edge-connected graph and a set of additional edges called links. Our goal is to find a set of links of minimum size whose addition to the graph makes it (k + 1)-edge-connected. There is an approximation preserving reduction from the mentioned problem to the case k = 1 (a.k.a. the Tree Augmentation Problem or TAP) or k = 2 (a.k.a. the Cactus Augmentation Problem or CacAP). While several better-than-2 approximation algorithms are known for TAP, for CacAP only recently this barrier was breached (hence for k-Connectivity Augmentation in general). As a first step towards better approximation algorithms for CacAP, we consider the special case where the input cactus consists of a single cycle, the Cycle Augmentation Problem (CycAP). This apparently simple special case retains part of the hardness of the general case. In particular, we are able to show that it is APX-hard. In this paper we present a combinatorial $\left (\frac {3}{2}+\varepsilon \right )$

3

2

+
ε

-approximation for CycAP, for any constant ε > 0. We also present an LP formulation with a matching integrality gap: this might be useful to address the general case of the problem.
Predictive value of De Ritis ratio in metastatic renal cell carcinoma treated with tyrosine-kinase inhibitors
Authors: Janisch Florian , Klotzbücher Thomas , Marks Phillip , Kienapfel Christina , Meyer Christian P. , Yu Hang , Fühner Constantin , Hillemacher Tobias , Mori Keiichiro , Mostafei Hadi , Shariat Shahrokh F. , Fisch Margit , Dahlem Roland , Rink Michael 
Published: March 2021

AbstractBackgroundPredictive markers can help tailor treatment to the individual in metastatic renal cell carcinoma (mRCC). De Ritis ratio (DRR) is associated with oncologic outcomes in various solid tumors.ObjectiveTo assess the value of DRR in prognosticating survival in mRCC patients treated with tyrosine-kinase inhibitors (TKI).MethodsOverall, 220 mRCC patients treated with TKI first-line therapy were analyzed. An optimal cut-off point for DRR was determined with Youden’s J. We used multiple strata for DRR, performed descriptive, Kaplan–Meier and multivariable Cox-regression analyses to assess associations of DRR with progression-free (PFS) and overall survival (OS).ResultsPatients above the optimal cut-off point for DRR of ≥ 1.58 had fewer liver metastases (p = 0.01). There was no difference in PFS (p > 0.05) between DRR groups. DRR above the median of 1.08 (HR 1.42;p = 0.03), DRR ≥ 1.1(HR 1.44;p = 0.02), ≥ 1.8 (HR 1.56;p = 0.03), ≥ 1.9 (HR 1.59;p = 0.02) and ≥ 2.0 (HR 1.63;p = 0.047) were associated with worse OS. These associations did not remain after multivariable adjustment. In the intermediate MSKCC group, DRR was associated with inferior OS at cut-offs ≥ 1.0 (HR 1.78;p = 0.02), ≥ 1.1 (HR 1.81;p = 0.01) and above median (HR 1.88;p = 0.007) in multivariable analyses. In patients with clear-cell histology, DRR above median (HR 1.54;p = 0.029) and DRR ≥ 1.1 (HR 1.53;p = 0.029) were associated with OS in multivariable analyses.ConclusionThere was no independent association between DRR and survival of mRCC patients treated with TKI in the entire cohort. However, OS of patients with intermediate risk and clear-cell histology were affected by DRR. DRR could be used for tailored decision-making in these subgroups.
A novel prediction model for the completion of six cycles of radium-223 treatment and survival in patients with metastatic castration-resistant prostate cancer
Authors: Miyoshi Yasuhide , Tsutsumi Sohgo , Yasui Masato , Kawahara Takashi , Uemura Ko-ichi , Hayashi Naruhiko , Nozawa Masahiro , Yoshimura Kazuhiro , Uemura Hiroji , Uemura Hirotsugu 
Published: March 2021

Abstract
Purpose
We evaluated the predictive factors for completion of all six cycles of radium-223 (Ra-223) treatment in patients with metastatic castration-resistant prostate cancer (mCRPC). We also developed a novel prediction model for Ra-223 treatment completion using these predictors.

Methods
We retrospectively reviewed data from 122 patients with mCRPC who were treated with Ra-223. The predictive factors for the completion of six cycles of Ra-223 treatment were evaluated. Statistically significant predictive factors were then used to develop a prediction model for treatment completion. Finally, using this prediction model, we classified the overall survival (OS) of the entire cohort into three groups.

Results
We identified three significant variables as the predictive factors for treatment completion: baseline alkaline phosphatase (ALP) level, baseline hemoglobin (Hb) level, and baseline pain. The three groups generated using the prediction model were: group 1 (patients with three predictive factors, i.e., ALP < median, Hb ≥ median, and no pain), group 2 (patients with one to two predictive factors), and group 3 (patients without any predictive factors). The treatment completion rates differed between the three groups significantly. Furthermore, the OS also differed among the groups significantly.

Conclusion
Our study suggested that the baseline ALP level, baseline Hb level, and baseline pain were the predictive factors of completion of all six cycles of Ra-223 treatment in patients with mCRPC. Our prediction model consisting of these factors could predict not only the completion of Ra-223 treatment, but also the post-treatment survival. This model can thus be useful for selection of patients for Ra-223 treatment.
Flow measurements in the wake of an adhering and oscillating droplet using laser-Doppler velocity profile sensor
Authors: Burgmann Sebastian , Dues Michael , Barwari Beawer , Steinbock Jonas , Büttner Lars , Czarske Jürgen , Janoske Uwe 
Published: March 2021

AbstractThe removal of droplets on surfaces by an (air-) flow is relevant, e.g., for cleaning processes or to prevent corrosion or damage of electronic devices. Still the condition for droplet movement is not fully understood. Droplets start to move downstream at a critical (air-) flow velocity vcrit. For increasing flow velocity, this process is related to a strong oscillation of the droplet. This oscillation is supposed to be a key mechanism for the onset of droplet movement in conjunction with the flow field around the droplet. We report on measurements in the wake of the adhering droplet by means of laser-Doppler velocity profile sensor and hot wire anemometry. Thanks to the excellent spatial and temporal resolution of laser-Doppler velocity profile sensor and its capability to measure bidirectional flows, a backflow region can be detected in the wake of the droplet. Therefore, it can be concluded that this backflow structure is the driving mechanism for the strong flow movement inside the droplet against channel flow direction found in previous work. Analyzing the frequency spectra of the flow velocity, it was found that the flow is also oscillating; frequency peaks are in the same range as for the contour oscillation. Based on frequency, diameter and flow velocity, a Strouhal number can be calculated. This Strouhal number is almost constant in the investigated regime of droplet volumes and is between 0.015 and 0.03. Therefore, it can be assumed that an aeroelastic self-excitation effect may be present that eventually leads to droplet movement.
Graphic abstract
High subsonic flow of an organic vapor past a circular cylinder
Authors: Reinker Felix , Wagner Robert , Hake Leander , der Wiesche Stefan aus 
Published: March 2021

AbstractA circular cylinder was tested in the cross-flow of an organic vapor (Novec™ 649) and of air over the subsonic (M < 0.4) and high subsonic (0.4 < M < 0.8) speed range in a continuously running pressurized closed-loop wind tunnel test facility. Time-averaged pressure measurements gave information on surface pressure distributions, and the corresponding drag and base pressure drag coefficients were obtained. Due to the charging of the wind tunnel, different values of the compressibility factor (0.876 < Z < 0.999) could be achieved for the organic vapor flow. This enabled in combination with the results for air an assessment of the impact of non-ideal gas dynamics on the form drag of a cylinder in the considered highly subsonic flow regime. The new experimental data were compared with available literature results. Changes in surface pressure distribution at higher subsonic velocities were identified and discussed. It was found that non-ideal gas effects did not strongly affect the overall drag. The variation of drag coefficient over the Mach number range was comparable with literature data for ideal-gas compressible flow, including shock-less and intermittent shock wave, and permanent shock wave flows regimes. At Mach 0.4, the flow of Novec™ 649 was in the shock-less regime and exhibited a pronounced dependency on the Reynolds number. An increase in drag was observed at Mach 0.6 which was attributed to the commencement of vortex shedding. Non-ideal thermodynamics only affected the flow locally and a reduction of the critical pressure coefficient in the high subsonic flow regime was observed in the surface pressure distribution. However, this mechanism did not alter significantly the overall drag behavior.Graphic abstractDrag coefficientCDagainst Re for several Mach numbersMand comparison with available literature results obtained for air (colored symbols indicate different Mach number clusters)
Intratumoral heterogeneity of surrogate molecular subtypes in urothelial carcinoma in situ of the urinary bladder: implications for prognostic stratification of high-risk non-muscle-invasive bladder cancer
Authors: Garczyk Stefan , Bischoff Felix , Schneider Ursula , Golz Reinhard , von Rundstedt Friedrich-Carl , Knüchel Ruth , Degener Stephan 
Published: March 2021

AbstractReliable factors predicting the disease course of non-muscle-invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) are unavailable. Molecular subtypes have potential for prognostic stratification of muscle-invasive bladder cancer, while their value for CIS patients is unknown. Here, the prognostic impact of both clinico-pathological parameters, including CIS focality, and immunohistochemistry-based surrogate subtypes was analyzed in a cohort of high-risk NMIBC patients with CIS. In 128 high-risk NMIBC patients with CIS, luminal (KRT20, GATA3, ERBB2) and basal (KRT5/6, KRT14) surrogate markers as well as p53 were analyzed in 213–231 biopsies. To study inter-lesional heterogeneity of CIS, marker expression in independent CIS biopsies from different bladder localizations was analyzed. Clinico-pathological parameters and surrogate subtypes were correlated with recurrence-free (RFS), progression-free (PFS), cancer-specific (CSS), and overall survival (OS). Forty-six and 30% of CIS patients exhibited a luminal-like (KRT20-positive, KRT5/6-negative) and a null phenotype (KRT20-negative, KRT5/6-negative), respectively. A basal-like subtype (KRT20-negative, KRT5/6-positive) was not observed. A significant degree of inter-lesional CIS heterogeneity was noted, reflected by 23% of patients showing a mixed subtype. Neither CIS surrogate subtype nor CIS focality was associated with patient outcome. Patient age and smoking status were the only potentially independent prognostic factors predicting RFS, PFS, OS, and PFS, respectively. In conclusion, further clarification of heterogeneity of surrogate subtypes in HR NMIBC and their prognostic value is of importance with regard to potential implementation of molecular subtyping into clinical routine. The potential prognostic usefulness of patient age and smoking status for high-risk NMIBC patients with CIS needs further validation.
Finding and Counting Permutations via CSPs
Authors: Berendsohn Benjamin Aram , Kozma László , Marx Dániel 
Published: March 2021

AbstractPermutation patterns and pattern avoidance have been intensively studied in combinatorics and computer science, going back at least to the seminal work of Knuth on stack-sorting (1968). Perhaps the most natural algorithmic question in this area is deciding whether a given permutation of lengthncontains a given pattern of lengthk. In this work we give two new algorithms for this well-studied problem, one whose running time is$$n^{k/4 + o(k)}$$nk/4+o(k), and a polynomial-space algorithm whose running time is the better of$$O(1.6181^n)$$O(1.6181n)and$$O(n^{k/2 + 1})$$O(nk/2+1). These results improve the earlier best bounds of$$n^{0.47k + o(k)}$$n0.47k+o(k)and$$O(1.79^n)$$O(1.79n)due to Ahal and Rabinovich (2000) resp. Bruner and Lackner (2012) and are the fastest algorithms for the problem when$$k \in \varOmega (\log {n})$$k∈Ω(logn). We show that both our new algorithms and the previous exponential-time algorithms in the literature can be viewed through the unifying lens ofconstraint-satisfaction. Our algorithms can alsocount, within the same running time, the number of occurrences of a pattern. We show that this result is close to optimal: solving the counting problem in time$$f(k) \cdot n^{o(k/\log {k})}$$f(k)·no(k/logk)would contradict theexponential-time hypothesis(ETH). For some special classes of patterns we obtain improved running times. We further prove that 3-increasing(4321-avoiding) and 3-decreasing(1234-avoiding) permutations can, in some sense,embedarbitrary permutations of almost linear length, which indicates that a sub-exponential running time is unlikely with the current techniques, even for patterns from these restricted classes.
A projected super-penalty method for the $$C^1$$-coupling of multi-patch isogeometric Kirchhoff plates
Authors: Coradello Luca , Loli Gabriele , Buffa Annalisa 
Published: March 2021

AbstractThis work focuses on the development of a super-penalty strategy based on the $$L^2$$

L
2

-projection of suitable coupling terms to achieve $$C^1$$

C
1

-continuity between non-conforming multi-patch isogeometric Kirchhoff plates. In particular, the choice of penalty parameters is driven by the underlying perturbed saddle point problem from which the Lagrange multipliers are eliminated and is performed to guarantee the optimal accuracy of the method. Moreover, by construction, the method does not suffer from boundary locking, especially on very coarse meshes. We demonstrate the applicability of the proposed coupling algorithm to Kirchhoff plates by studying several benchmark examples discretized by non-conforming meshes. In all cases, we recover the optimal rates of convergence achievable by B-splines where we achieve a substantial gain in accuracy per degree-of-freedom compared to other choices of the penalty parameters.