New approach to the visualization of international scientific collaboration

Chinchilla-Rodríguez, Z., Vargas-Quesada, B., Hassan-Montero, Y., González-Molina, A., Moya-Anegón, F. New approach to the visualization of international scientific collaboration. Information Visualization, 9 (4): 277-287, Winter 2010. DOI: 10.1057/ivs.2009.31In this study, visual representations are created in order to analyze different aspects of scientific collaboration at the international level. The main objective is to identify the international facet of research by following the flow of knowledge as expressed by the number of scientific publications, and then establishes the main geographical axes of output, showing the interrelationships of the domain, the intensity of these relations, and how the different types of collaboration are reflected in terms of visibility. Thus, the methodology has a twofold application, allowing us to detect significant differences that help characterize patterns of behaviour of a geographical system of output, along with the generation of representations that serve as interfaces for domain analysis and information retrieval.Peer reviewe

Hair Transplantation in the United States: A Population-based Survey of Female and Male Pattern Baldness

Background: Androgenetic alopecia, the most common type of hair loss, can impair the patient’s overall mental health. Although there are pharmaceutical and surgical treatments available, little is known about the public standpoint toward hair transplantation (HT). Methods: A sample of individuals living in the United States (n = 1000; male and female participants were equally distributed) was asked to fill out the questionnaire. The online survey was conducted in June 2022. Results: Most participants (42%; n = 416) were between 41 and 60 years of age. Study participants frequently reported that, with their hair loss progressing, they would not feel attractive anymore (n = 400; 40%), nor as confident as before (n = 330; 33%). Although women with minimal hair loss were willing to spend a median price of $4000 [interquartile range (IQ) IQR$1000–$5000], women with extensive hair loss were willing to spend significantly more (median =$5000; IQR $3600–$6375; P = 0.011). This was reproducible in men (P = 0.033). Although significantly fewer women considered undergoing HT (430 women versus 447 men; P < 0.001), female participants were willing to pay more for their HT compared with men (P = 0.039). Conclusions: Individuals living in the United States consider hair loss to impair their attractiveness and regard HT as a valuable therapeutic option. More affordable and gender-specific HT should be subject to future research work

Gas‐Phase Transformation of Fluorinated Benzoporphyrins to Porphyrin‐Embedded Conical Nanocarbons

Geodesic nitrogen‐containing graphene fragments are interesting candidates for various material applications, but the available synthetic protocols, which need to overcome intrinsic strain energy during the formation of the bowl‐shaped skeletons, are often incompatible with heteroatom‐embedded structures. Through this mass spectrometry‐based gas‐phase study, we show by means of collision‐induced dissociation experiments and supported by density functional theory calculations, the first evidence for the formation of a porphyrin‐embedded conical nanocarbon. The influences of metalation and functionalization of the used tetrabenzoporphyrins have been investigated, which revealed different cyclization efficiencies, different ionization possibilities, and a variation of the dissociation pathway. Our results suggest a stepwise process for HF elimination from the fjord region, which supports a selective pathway towards bent nitrogen‐containing graphene fragments

The significance of the extent of tissue embedding for the detection of incidental prostate carcinoma on transurethral prostate resection material: the more, the better?

The aim of this study is to investigate the incidental prostate cancer (iPCa) detection rates of different embedding methods in a large, contemporary cohort of patients with bladder outlet obstruction (BOO) treated with transurethral surgery. We relied on an institutional tertiary-care database to identify BOO patients who underwent either transurethral loop resection or laser (Holmium:yttrium–aluminium garnet) enucleation of the prostate (HoLEP) between 01/2012 and 12/2019. Embedding methods differed with regard to the extent of the additional prostate tissue submitted following the first ten cassettes of primary embedding (cohort A: one [additional] cassette/10 g residual tissue vs. cohort B: complete embedding of the residual tissue). Detection rates of iPCa among the different embedding methods were compared. Subsequently, subgroup analyses by embedding protocol were repeated in HoLEP-treated patients only. In the overall cohort, the iPCa detection rate was 11% (46/420). In cohort A (n = 299), tissue embedding resulted in a median of 8 cassettes/patient (range 1–38) vs. a median of 15 (range 2–74) in cohort B (n = 121) (p < .001). The iPCa detection rate was 8% (23/299) and 19% (23/121) in cohort A vs. cohort B, respectively (p < .001). Virtual reduction of the number of tissue cassettes to ten cassettes resulted in a iPCa detection rate of 96% in both cohorts, missing one stage T1a/ISUP grade 1 carcinoma. Increasing the number of cassettes by two and eight cassettes, respectively, resulted in a detection rate of 100% in both cohorts without revealing high-grade carcinomas. Subgroup analyses in HoLEP patients confirmed these findings, demonstrated by a 100 vs. 96% iPCa detection rate following examination of the first ten cassettes, missing one case of T1a/ISUP 1. Examination of 8 additional cassettes resulted in a 100% detection rate. The extent of embedding of material obtained from transurethral prostate resection correlates with the iPCa detection rate. However, the submission of 10 cassettes appears to be a reasonable threshold to reduce resource utilization while maintaining secure cancer detection

Characterization of Porphyrin-Co(III)-'Nitrene Radical' Species Relevant in Catalytic Nitrene Transfer Reactions

To fully characterize the Co-III-'nitrene radical' species that are proposed as intermediates in nitrene transfer reactions mediated by cobalt(II) porphyrins, different combinations of cobalt(II) complexes of porphyrins and nitrene transfer reagents were combined, and the generated species were studied using EPR, UV-vis, IR, VCD, UHR-ESI-MS, and XANES/XAFS measurements. Reactions of cobalt(II) porphyrins 1(P1) (P1 = meso-tetraphenylporphyrin (TPP)) and 1(P2) (P2 = 3,5-Di(t)Bu-ChenPhyrin) with organic azides 2(Ns) (NsN(3)), 2(Ts) (TsN3), and 2(Troc) (TrocN(3)) led to the formation of mono-nitrene species 3(Ns)(P1), 3(Ts)(P2), and 3(Troc)(P2), respectively, which are best described as [Co-III(por)(NR ''(center dot-))] nitrene radicals (imidyl radicals) resulting from single electron transfer from the cobalt(II) porphyrin to the 'nitrene' moiety (Ns: R '' = -SO2-p-C6H5NO2; Ts: R '' = -SO2C6H6; Troc: R '' = -C(O)OCH2CCl3). Remarkably, the reaction of 1(P1) with N-nosyl iminoiodane (PhI=NNs) 4(Ns) led to the formation of a bis-nitrene species 5(Ns)(P1). This species is best described as a triple-radical complex [(por ''(center dot-))Co-III(NR ''(center dot-))(2)] containing three ligand-centered unpaired electrons: two nitrene radicals (NR?(-)) and one oxidized porphyrin radical (por(center dot-)). Thus, the formation of the second nitrene radical involves another intramolecular one-electron transfer to the "nitrene" moiety, but now from the porphyrin ring instead of the metal center. Interestingly, this bis-nitrene species is observed only on reacting 4(Ns) with 1(P1). Reaction of the more bulky 1(P2) with 4(Ns) results again in formation of mainly mono-nitrene species 3(Ns)(P2) according to EPR and ESI-MS spectroscopic studies. The mono- and bis-nitrene species were initially expected to be five- and six-coordinate species, respectively, but XANES data revealed that both mono- and bis-nitrene species are six-coordinate Oh species. The nature of the sixth ligand bound to cobalt(III) in the mono-nitrene case remains elusive, but some plausible candidates are NH3, NH2-, NsNH(-), and OH-; NsNH(-) being the most plausible. Conversion of mono-nitrene species 3(Ns)(P1) into bis-nitrene species 5(Ns)(P1) upon reaction with 4(Ns) was demonstrated. Solutions containing 3(Ns)(P1) and 5(Ns)(P1) proved to be still active in catalytic aziridination of styrene, consistent with their proposed key involvement in nitrene transfer reactions mediated by cobalt(II) porphyrins