A Mixed-Valence Ti(II)/Ti(III) Inverted Sandwich Compound as a Regioselective Catalyst for the Uncommon 1,3,5-Alkyne Cyclotrimerization.

The synthesis, structure, and catalytic activity of a Ti(II)/Ti(III) inverted sandwich compound are presented in this study. Synthesis of the arene-bridged dititanium compound begins with the preparation of the titanium(IV) precursor [TiCl2(MesPDA)(thf)2] (MesPDA = N,N'-bis(2,4,6-trimethylphenyl)-o-phenylenediamide) (2). The reduction of 2 with sodium metal results in species [{Ti(MesPDA)(thf)}2(µ-Cl)3{Na}] (3) in oxidation state III. To achieve the lower oxidation state II, 2 undergoes reduction through alkylation with lithium cyclopentyl. This alkylation approach triggers a cascade of reactions, including ß-hydride abstraction/elimination, hydrogen evolution, and chemical reduction, to generate the Ti(II)/Ti(III) compound [Li(thf)4][(TiMesPDA)2(µ-η6: η6-C6H6)] (4). X-ray and EPR characterization confirms the mixed-valence states of the titanium species. Compound 4 catalyzes a mild, efficient, and regiospecific cyclotrimerization of alkynes to form 1,3,5-substituted arenes. Kinetic data support a mechanism involving a binuclear titanium arene compound, similar to compound 4, as the resting state. The active catalyst promotes the oxidative coupling of two alkynes in the rate-limiting step, followed by a rapid [4 + 2] cycloaddition to form the arene product. Computational analysis of the resting state for the cycloaddition of trimethylsilylacetylene indicates a thermodynamic preference for stabilizing the 1,3,5-arene within the space between the two [TiMesPDA] fragments, consistent with the observed regioselectivity.

Analysis and prediction of long-term survival using a clinically applicable risk score based on the Electronic Health Record.

BACKGROUND: The long-term survival of a population assigned to a hospital can be essential to anticipate, manage, and provide appropriate hospital healthcare resources or lead preventive actions for high-risk mortality individuals. In this study, we discriminate which electronic health record variables are most relevant to predict the long-term survival of a population, and apply the results to identify high-risk mortality groups. MATERIALS AND METHODS: A prospective cohort study was conducted on a population of 113,403 individuals alive on July 1st, 2018 from the General Hospital of Castellón (Spain). Considering electronic health record patients' variables and survival days from the start date of the study, a Kaplan-Meier analysis and a multivariate Cox regression model were performed, and a risk score based on Cox coefficients was applied to predict survival over 3 years. RESULTS: All significant covariates from the Cox model (91.5% c-index) were associated with increased mortality risk. Using the proposed risk score, Kaplan-Meier curves show that survival probability in the 3rd year is 99.23% (95% confidence interval (CI) 99.18-99.29) for the low-risk, 91.21% (95% CI 90.67-91.76) for medium-risk, 76.52% (95% CI 75.59-77.46) for the high-risk, and 48.61 % (95% CI 46.85-50.36) for the very high-risk groups. DISCUSSION: The Cox model obtained is highly predictive, and it has been found that some electronic health record variables little studied to date, such as Clinical Risk Groups, have a strong impact on survival. Regarding clinical application, the proposed risk score is particularly useful for identifying high-risk subpopulations within a large population.

Ti(III) Catalysts for CO2/Epoxide Copolymerization at Unusual Ambient Pressure Conditions.

Titanium compounds in low oxidation states are highly reducing species and hence powerful tools for the functionalization of small molecules. However, their potential has not yet been fully realized because harnessing these highly reactive complexes for productive reactivity is generally challenging. Advancing this field, herein we provide a detailed route for the formation of titanium(III) orthophenylendiamido (PDA) species using [LiBHEt3] as a reducing agent. Initially, the corresponding lithium PDA compounds [Li2(ArPDA)(thf)3] (Ar = 2,4,6-trimethylphenyl (MesPDA), 2,6-diisopropylphenyl (iPrPDA)) are combined with [TiCl4(thf)2] to form the heterobimetallic complexes [{TiCl(ArPDA)}(µ-ArPDA){Li(thf)n}] (n = 1, Ar = iPr 3 and n = 2, Ar = Mes 4). Compound 4 evolves to species [Ti(MesPDA)2] (6) via thermal treatment. In contrast, the transformation of 3 into [Ti(iPrPDA)2] (5) only occurs in the presence of [LiNMe2], through a lithium-assisted process, as revealed by density functional theory (DFT). Finally, the Ti(IV) compounds 3-6 react with [LiBHEt3] to give rise to the Ti(III) species [Li(thf)4][Ti(ArPDA)2] (Ar = iPr 8, Mes 9). These low-valent compounds in combination with [PPN]Cl (PPN = bis(triphenylphosphine)iminium) are proved to be highly selective catalysts for the copolymerization of CO2 and cyclohexene epoxide. Reactions occur at 1 bar pressure with activity/selectivity levels similar to Salen-Cr(III) compounds.

Reductive Hydrogenation of Sulfido-Bridged Tantalum Alkyl Complexes: A Mechanistic Insight.

Hydrogenolysis of a series of alkyl sulfido-bridged tantalum(IV) dinuclear complexes [Ta(η5-C5Me5)R(µ-S)]2 [R = Me, nBu (1), Et, CH2SiMe3, C3H5, Ph, CH2Ph (2), p-MeC6H4CH2 (3)] has led quantitatively to the Ta(III) tetrametallic sulfide cluster [Ta(η5-C5Me5)(µ3-S)]4 (4) along with the corresponding alkane. Mechanistic information for the formation of the unique low-valent tetrametallic compound 4 was gathered by hydrogenation of the phenyl-substituted precursor [Ta(η5-C5Me5)Ph(µ-S)]2, which proceeds through a stepwise hydrogenation process, disclosing the formation of the intermediate tetranuclear hydride sulfide [Ta2(η5-C5Me5)2(H)Ph(µ-S)(µ3-S)]2 (5). Extending our studies toward tantalum alkyl precursors containing functional groups susceptible to hydrogenation, such as the allyl-and benzyl-substituted compounds [Ta(η5-C5Me5)(η3-C3H5)(µ-S)]2 and [Ta(η5-C5Me5)(CH2Ph)(µ-S)]2 (2), enables alternative reaction pathways en route to the formation of 4. In the former case, the dimetallic system undergoes selective hydrogenation of the unsaturated allyl moiety, forming the asymmetric complex [{Ta(η5-C5Me5)(η3-C3H5)}(µ-S)2{Ta(η5-C5Me5)(C3H7)}] (6) with only one propyl fragment. Species 2, in addition to the hydrogenation of one benzyl fragment and concomitant toluene release, also undergoes partial hydrogenation and dearomatization of the phenyl ring on the vicinal benzyl unity to give a η5-cyclohexadienyl complex [Ta2(η5-C5Me5)2(µ-CH2C6H6)(µ-S)2] (7). The mechanistic implications of the latter hydrogenation process are discussed by means of DFT calculations.

Severe pembrolizumab-induced gastritis in a patient with lung adenocarcinoma.

Cancer immunotherapy is an increasingly common treatment option based on anti-tumor immune response. However, a challenge is arising regarding its potential, which is the poorly understood recognized immune-mediated adverse effects.

Complications and diagnostic accuracy of CT-guided 18G tru-cut versus end-cut percutaneous core needle biopsy of solitary solid lung nodules.

PURPOSE: Percutaneous biopsy has demonstrated high accuracy in diagnosis of lung nodules, but the technique is not innocuous and a yield decrease in lesions smaller than 20 mm has been reported. We carried out a prospective study to evaluate and compare the complications and efficacy of percutaneous core needle biopsy (CNB) of solitary solid lung nodules, which were performed with two types of automatic guns. METHODS: 330 consecutive CT-guided CNB were included. Tru-cut or end-cut 18G devices were used alternatively. Nodules were categorized by their size: ≤10 mm, 11-20 mm and >20 mm. Incidence of complications such as pneumothorax or hemoptysis and factors influencing them (nodule size and depth within lung parenchyma) were evaluated. Diagnostic accuracy of CNB achieved in the three groups of nodules regarding the two different needles were calculated and statistically evaluated and compared. RESULTS: We performed 68 CNB in nodules ≤10 mm, 130 in 11-20 mm and 132 in >20 mm. Pneumothorax appeared in 24.2% of them, but only 5.7% required drainage. Hemoptysis was developed in 9.4% and abundant hemoptysis with hypoxemia was observed in only 4.2% of patients. Regarding appearance of complications between the two needle types, no significant differences were found. A higher risk of hemoptysis was observed in nodules ≤10 mm (OR = 3.87; 95% CI = 1.24-12.06, P = 0.019) and in those located deeper in pulmonary parenchyma (OR = 2.21; 95% CI = 1.04-4.69, P = 0.038). End-cut needles reached a diagnostic accuracy of 93.7%, 92.1% and 98.3%, in nodules sized ≤10 mm, 11-20 mm and >20 mm, respectively. Corresponding results for tru-cut were 84.7%, 88.5% and 92.1%. In spite of differences reaching up to 9% in smaller nodules, intra-group results were not significant. CONCLUSION: Both needles have similar complications rate. Despite not having observed statistically significant differences between the two types of needles, end-cut devices have demonstrated a higher diagnostic yield in the three groups of nodules and could be a more suitable option especially for CNB of nodules ≤10 mm.

N═N Bond Cleavage by Tantalum Hydride Complexes: Mechanistic Insights and Reactivity.

The reaction of [TaCpRX4] (CpR = η5-C5Me5, η5-C5H4SiMe3, η5-C5HMe4; X = Cl, Br) with SiH3Ph resulted in the formation of the dinuclear hydride tantalum(IV) compounds [(TaCpRX2)2(µ-H)2], structurally identified by single-crystal X-ray analyses. These species react with azobenzene to give the mononuclear imide complex [TaCpRX2(NPh)] along with the release of molecular hydrogen. Analogous reactions between the [{Ta(η5-C5Me5)X2}2(µ-H)2] derivatives and the cyclic diazo reagent benzo[c]cinnoline afford the biphenyl-bridged (phenylimido)tantalum complexes [{Ta(η5-C5Me5)X2}2(µ-NC6H4C6H4N)] along with the release of molecular hydrogen. When the compounds [(TaCpRX2)2(µ-H)2] (CpR = η5-C5H4SiMe3, η5-C5HMe4; X = Cl, Br) were employed, we were able to trap the side-on-bound diazo derivatives [(TaCpRX)2{µ-(η2,η2-NC6H4C6H4N)}] (CpR = η5-C5H4SiMe3, η5-C5HMe4; X = Cl, Br) as intermediates in the N═N bond cleavage process. DFT calculations provide insights into the N═N cleavage mechanism, in which the ditantalum(IV) fragment can promote two-electron reductions of the N═N bond at two different metal-metal bond splitting stages.

Major Prehospital Trauma and In-Hospital Emergencies: Massive Transfusion Triggers.

BACKGROUND: Massive transfusion (MT) in trauma is initiated on the basis of factors of different natures and depending on protocols and scales used both in prehospital and in-hospital care areas. OBJECTIVE: The main goal was to analyze and relate factors and predictive variables for MT requirements considering both health care areas. METHOD: This was a retrospective cohort study that included patients who were treated either at the emergency department of a large hospital or through prehospital care before arrival at the hospital. The patients included were adults who received MT, defined as a blood bank request of 10 or more units of red cells in the first 24 hours or 5 or more within 4 hours of trauma, from January 1, 2009, to January 1, 2017. The variables included were individual characteristics and those associated with the trauma, clinical-analytical assessment, resuscitation, timing, and survival. RESULTS: A total of 52 patients who received MT were included. The average age of the patients was 41.23 ± 16.06 years, a mean of 19.56 ± 12.77 units was administered, and the mortality rate was 21.2%. DISCUSSION: Injury mechanism, clinical-analytical variables, and resuscitation strategies have a significant influence on the need for MT; therefore, early identification is fundamental for performing quality management and addressing avoidable factors during MT processes.

Angioedema hereditario tipo III en una embarazada: a propósito de un caso / Hereditary angioedema type III in pregnant women: case report and literature review

Resumen ANTECEDENTES: El angioedema hereditario es una enfermedad rara, caracterizada por episodios recurrentes de edema en cualquier parte del cuerpo, sobre todo en las extremidades, la cara y las vías respiratorias. Existen tres tipos de enfermedad en función de su causa, el menos frecuente es el III con un nivel y función del inhibidor de C1 normales. Su fisiopatología es poco conocida; por lo tanto, su diagnóstico es difícil. Su tratamiento ha avanzado en los últimos años, aunque queda mucho por definir, sobre todo durante el embarazo. OBJETIVO: Evaluar la bibliografía disponible relacionada con el angioedema hereditario y su atención médica en mujeres embarazadas. CASO CLÍNICO: Paciente de 30 años, en curso de su primer embarazo. El único antecedente personal destacable fue haber padecido angioedema hereditario tipo III, diagnosticado 10 años antes después de varios episodios de angioedema orofacial. A lo largo del embarazo sobrevinieron varias crisis de la enfermedad que requirieron tratamiento de los episodios agudos y de mantenimiento en el tercer trimestre. Por último, ocurrió un parto instrumentado mediante vaccum, por riesgo de pérdida de bienestar fetal con buen desenlace materno y fetal en el posparto inmediato. CONCLUSIONES: El angioedema hereditario tipo III es una enfermedad muy rara y poco conocida en la Ginecoobstetricia que requiere establecer un protocolo y estandarización de la atención clínica, sobre todo en las embarazadas, lo que ayudará a proporcionar una información y asistencia de calidad a estas pacientes.

Abstract BACKGROUND: Hereditary angioedema is a rare disease characterized by recurrent episodes of edema anywhere in the body, especially in the extremities, face and airways. There are three types of the disease depending on its cause, the most infrequent being III with normal C1 inhibitor level and function. Its pathophysiology is poorly understood; therefore, its diagnosis is difficult. Its treatment has advanced in recent years, although much remains to be defined, especially during pregnancy. OBJECTIVE: To evaluate the available literature related to hereditary angioedema and its medical care in pregnant women. CLINICAL CASE: 30-year-old female patient, during her first pregnancy. The only personal history of note was hereditary angioedema type III, diagnosed 10 years earlier after several episodes of orofacial angioedema. Throughout the pregnancy, several crises of the disease occurred, requiring treatment in acute episodes and maintenance treatment in the third trimester. Finally, one delivery was instrumented by vaccum, due to risk of loss of fetal well-being with good maternal and fetal outcome in the immediate postpartum period. CONCLUSIONS: Hereditary angioedema type III is a very rare and little-known disease that requires establishing a protocol and standardization of clinical care, especially in pregnant women, which will help to provide quality information and assistance to these patients.

Proposal of a clinical care pathway for quality and safe management of headache patients: a consensus study report.

BACKGROUND: Headache is one of the most prevalent and disabling conditions. Its optimal management requires a coordinated and comprehensive response by health systems, but there is still a wide variability that compromises the quality and safety of the care process. PURPOSE: To establish the basis for designing a care pathway for headache patients through identifying key subpathways in the care process and setting out quality and clinical safety standards that contribute to providing comprehensive, adequate and safe healthcare. METHOD: A qualitative research study based on the consensus conference technique. Eleven professionals from the Spanish National Health System participated, seven of them with clinical experience in headache and four specialists in healthcare management and quality. First, identification of the key subpathways in the care process for headache, barriers/limitations for optimal quality of care, and quality and safety standards applied in each subpathway. Second, two consecutive consensus rounds were carried out to assess the content of the subpathway level descriptors, until the expert agreement was reached. Third, findings were assessed by 17 external healthcare professionals to determine their understanding, adequacy and usefulness. RESULTS: Seven key subpathways were identified: (1) primary care, (2) emergency department, (3) neurology department, (4) specialised headache unit, (5) hospitalisation, (6) outpatients and (7) governance and management. Sixty-seventh barriers were identified, the most frequent being related to diagnostic errors (36,1%), resource deficiency (25%), treatment errors (19,4%), lack of health literacy (13,9%) and inadequate communications with care transitions (5,6%). Fifty-nine quality and 31 safety standards were defined. They were related to evaluation (23.3%), patient safety (21.1%), comprehensive care (12.2%), treatment (12.2%), clinical practice guidelines (7.8%), counselling (6.7%), training (4.4%) and patient satisfaction (3.3%). CONCLUSIONS: This proposal incorporates a set of indicators and standards, which can be used to define a pathway for headache patients and determine the levels of quality.

Ureteroarterial fistula treated by endovascular stent placement.

A 69-year-old woman with changes secondary to pelvic radiotherapy presents repeated episodes of massive hematuria associated with double J catheter replacements. After several imaging tests, an uretero-arterial fistula is confirmed by angiography and treated with a coated stent. Uretero-arterial fistula poses a diagnostic challenge, requiring a multidisciplinary approach through clinical suspicion and interventional procedures.

Lymph Node Ratio, Perineural Invasion and R1 Resection as Independent Prognostic Factors in Pancreatic Adenocarcinoma: A Retrospective Cohort Study.

INTRODUCTION: The prognosis of pancreatic ductal adenocarcinoma has been associated with several factors. The aim of the present study was to correlate tumor-related factors and pathological findings with disease-free survival (DFS) and overall survival (OS) in patients undergoing pancreaticoduodenectomy. MATERIAL AND METHODS: From a prospectively maintained database, we reviewed 89 pancreatic ductal adenocarcinomas in patients who underwent pancreaticoduodenectomy from 2010 to 2014. The impact of histopathologic or tumor-related data, including a lymph node ratio greater than 15% (LNR15), on survival was analyzed. RESULTS: Univariate analysis of DFS and OS showed that vascular resection, pT, pN, LNR15, microvascular, lymphatic, and perineural invasion, and R1 resection influenced survival. Only LNR15, perineural invasion and R1 resection were independent predictors for both DFS (HR 6.39, p = 0.011; HR 8.53, p = 0.003; HR 9.68, p = 0.002, respectively) and OS (HR 4.21, p = 0.039; HR 5.41, p = 0.020; HR 4.41, p = 0.036, respectively). CONCLUSIONS: This study demonstrates that LNR15, perineural invasion and R1 resection are independently associated with DFS and OS.

A Bridging bis-Allyl Titanium Complex: Mechanistic Insights into the Electronic Structure and Reactivity.

Treatment of the dinuclear compound [{Ti(η5-C5Me5)Cl2}2(µ-O)] with allylmagnesium chloride provides the formation of the allyltitanium(III) derivative [{Ti(η5-C5Me5)(µ-C3H5)}2(µ-O)] (1), structurally identified by single-crystal X-ray analysis. Density functional theory (DFT) calculations confirm that the electronic structure of 1 is a singlet state, and the molecular orbital analysis, along with the short Ti-Ti distance, reveal the presence of a metal-metal single bond between the two Ti(III) centers. Complex 1 reacts rapidly with organic azides, RN3 (R = Ph, SiMe3), to yield the allyl µ-imido derivatives [{Ti(η5-C5Me5)(CH2CH═CH2)2}2(µ-NR)(µ-O)] [R = Ph(2), SiMe3(3)] along with molecular nitrogen release. Reaction of 2 and 3 with H2 leads to the µ-imido propyl species [{Ti(η5-C5Me5)(CH2CH2CH3)2}2(µ-NR)(µ-O)] [R = Ph(4), SiMe3(5)]. Theoretical calculations were used to gain insight into the hydrogenation mechanism of complex 3 and rationalize the lower reactivity of 2. Initially, the µ-imido bridging group in these complexes activates the H2 molecule via addition to the Ti-N bonds. Subsequently, the titanium hydride intermediates induce a change in hapticity of the allyl ligands, and the nucleophilic attack of the hydride to the allyl groups leads to metallacyclopropane intermediates. Finally, the proton transfer from the amido group to the metallacyclopropane moieties affords the propyl complexes 4 and 5.

Molecular Design of Cyclopentadienyl Tantalum Sulfide Complexes.

Use of (Me3Si)2S and [Ta(η5-C5Me5)Cl4] (1) in a 4:3 ratio afforded the trimetallic sulfide cluster [Ta3(η5-C5Me5)3Cl3(µ3-Cl)(µ-S)3(µ3-S)] (2) with loss of SiClMe3. A similar reaction between 1, TaCl5, and (Me3Si)2S in a 2:1:4 ratio resulted in the analogous complex [Ta3(η5-C5Me5)2Cl4(µ3-Cl)(µ-S)3(µ3-S)] (3). Single-crystal X-ray diffraction analyses of 2 and 3 showed in all cases trinuclear tantalum sulfide clusters. On the other hand, thermal treatment of 2 with SiH3Ph generated very cleanly the dinuclear tantalum(IV) sulfide complex [Ta2(η5-C5Me5)2Cl2(µ-S)2] (4) in a quantitative way. Likewise, we found that 4 was synthesized more easily by a one-pot reaction of 1, (Me3Si)2S, and SiH3Ph in toluene. Reactions of 4 with a series of alkylating reagents rendered the dinuclear peralkylated sulfide complexes [Ta2(η5-C5Me5)2R2(µ-S)2] (R = Me 5, Et 6, CH2SiMe3 7, C3H5 8, Ph 9). Single-crystal X-ray diffraction analyses of 4, 5, and 9 showed in all cases a trans disposition of the chloro or alkyl substituents. The short Ta-Ta distances (2.918(1)-2.951(1) Å) along with DFT calculations indicate a σ-Ta-Ta interaction. Complexes 5, 6, and 8 undergo trans- cis isomerization, and mechanistic proposals are discussed based on DFT calculations.

Massive transfusion triggers in severe trauma: Scoping review.

OBJECTIVE: to identify the predictive variables or the massive transfusion triggers in severely traumatized patients through the existing scales. METHOD: a review of the literature was carried out using the Scoping Review method across the electronic databases CINAHL, MEDLINE, LILACS, the Cochrane and IBECS libraries, and the Google Scholar search tool. RESULTS: in total, 578 articles were identified in the search and the 36 articles published in the last ten years were included, of which 29 were original articles and 7 review articles. From the analysis, scales for massive transfusion and their predictive triggers were examined. CONCLUSION: the absence of universal criteria regarding the massive transfusion triggers in traumatized patients has led to the development of different scales, and the studies on their validation are considered relevant for the studies about when to initiate this strategy.

Massive transfusion triggers in severe trauma: Scoping review / Desencadeantes de transfusão maciça em trauma grave: Scoping review / Triggers de transfusión masiva en el trauma grave: Scoping review

Objective to identify the predictive variables or the massive transfusion triggers in severely traumatized patients through the existing scales. Method a review of the literature was carried out using the Scoping Review method across the electronic databases CINAHL, MEDLINE, LILACS, the Cochrane and IBECS libraries, and the Google Scholar search tool. Results in total, 578 articles were identified in the search and the 36 articles published in the last ten years were included, of which 29 were original articles and 7 review articles. From the analysis, scales for massive transfusion and their predictive triggers were examined. Conclusion the absence of universal criteria regarding the massive transfusion triggers in traumatized patients has led to the development of different scales, and the studies on their validation are considered relevant for the studies about when to initiate this strategy.

Objetivo identificar as variáveis preditivas ou os desencadeantes de transfusão maciça em pacientes com trauma grave através das escalas existentes. Método foi realizada uma revisão da literatura utilizando o método Scoping Review, nas bases de dados eletrônicas CINAHL, MEDLINE, LILACS, nas bibliotecas Cochrane e IBECS, e a ferramenta de busca do Google Scholar. Resultados foram identificados 578 artigos na pesquisa no total, dos quais foram incluídos os 36 artigos publicados nos últimos dez anos, sendo 29 artigos originais e 7 artigos de revisão. A partir da análise, foram examinadas as escalas de transfusão maciça e seus desencadeantes preditivos. Conclusão a falta de critérios universais com relação aos desencadeadores de transfusão em maciça em pacientes traumatizados levou à criação de diferentes escalas, sendo os estudos sobre sua validação considerados importantes para as estudos sobre quando iniciar essa estratégia.

Objetivo identificar las variables predictivas o los triggers de transfusión masiva en el paciente traumatizado grave a través de las escalas existentes. Método se realizó una revisión de la literatura mediante el método Scoping Review, en las bases de datos electrónicas CINAHL, MEDLINE, LILACS, las bibliotecas Cochrane e IBECS, y el buscador Google Scholar. Resultados un total de 578 artículos fueron identificados en la búsqueda, de los cuales, se incluyeron un total de 36 publicados en los últimos diez años, distribuidos en 29 originales y 7 de revisión. Del análisis, se examinaron las escalas de transfusión masiva y sus triggers predictivos. Conclusión la inexistencia de criterios universales respecto a los triggers de transfusión masiva en el paciente traumatizado ha traído consigo la creación de diferentes escalas, donde los estudios de validación de las mismas se detectan como relevantes para la investigación sobre cuando iniciar esta estrategia.

An Effective Route to Dinuclear Niobium and Tantalum Imido Complexes.

Thermal treatment of the trichloro complexes [MCl3(NR)py2] (R = tBu, Xyl; M = Nb, Ta) (Xyl = 2,6-Me2C6H3) under vacuum affords the dinuclear imido species [MCl2(µ-Cl)(NR)py]2 (R = tBu, Xyl; M = Nb 1, 3; Ta 2, 4) with loss of pyridine. Complexes 1-4 can be easily transformed to the mononuclear starting materials [MCl3(NR)py2] (R = tBu, Xyl; M = Nb, Ta) upon reaction with pyridine. While reactions of compounds 1 and 2 with a series of alkylating reagents render the mononuclear peralkylated imido complexes [MR3(NtBu)] (R = Me, CH2Ph, CH2CMe3, CH2CMePh, CH2SiMe3), the analogous treatment with allylmagnesium chloride results in the formation of the dinuclear niobium(IV) derivative [(NtBu)(η3-C3H5)M(µ-C3H5)(µ-Cl)2M(NtBu)py2] (5). Additionally, the treatment of the starting materials 1 and 2 with the organosilicon reductant 1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene yields the pyridyl-bridged dinuclear derivatives [M2Cl2(µ-Cl)2(NtBu)2py2]2(µ-NC4H4N)2 (M = Nb 6, Ta 7). Controlled hydrolysis reaction of 1 and 2 affords the oxo chlorido-bridged products [MCl(µ-Cl)(NtBu)py]2(µ-O) (M = Nb 8, Ta 9) in a quantitative way, while the treatment of these latter with one more equivalent of pyridine led to complexes [MCl2(NtBu)py2]2(µ-O) (M = Nb 10, Ta 11). Structural study of these dinuclear imido derivatives has been also performed by X-ray crystallography.

Preservación de la fertilidad en cáncer de mama: caso clínico / Preservation of fertility in breast cancer: a clinical case

El cáncer de mama es la neoplasia más frecuente en la mujer. Actualmente estas pacientes tienen altas tasas de supervivencia, aunque derivado del tratamiento quimioterápico sufren riesgo de fallo ovárico prematuro y/o pérdida de reserva folicular. La preservación de la fertilidad debe ser ofertada a las pacientes oncológicas jóvenes con deseos genésicos. La técnica de elección es la vitrificación de ovocitos, ya que se trata de una técnica consolidada y se evita la generación de embriones con un futuro incierto (AU)

Breast cancer is the most frequent tumor in women; nowadays these patients have high survival rates, although due to chemotherapy they are at risk of premature ovary failure. Preservation of fertility should be offered to young oncological patients who desire to have children. The elective technique is the oocyte vitrification, since it is considered an established technique and it avoids the creation of embryos with unknown future (AU)

Systematic Approach for the Construction of Niobium and Tantalum Sulfide Clusters.

Treatment of the imido complexes [MCl3(NR)py2] (R = (t)Bu, 2,6-Me2C6H3; M = Nb 1, 3; Ta 2, 4) (Xyl = 2,6-Me2C6H3) with (Me3Si)2S in a 1:1 ratio afforded the new cube-type sulfide clusters [MCl(NR)py(µ3-S)]4 (R = (t)Bu, 2,6-Me2C6H3; M = Nb 5, 7; Ta 6, 8) with loss of Me3SiCl. Reactions of 5 and 6 with cyclopentadienyllithium in 1:4 ratio resulted in the rupture of the coordinative M-S bonds and the replacement of a pyridine molecule and a chlorine atom by an η(5)-cyclopentadienyl group in each metal center, affording the compounds [M(η(5)-C5H5)(N(t)Bu)(µ-S)]4 (M = Nb 9, Ta 10). These processes may develop through formation of the complexes [M4(η(5)-C5H5)2(µ-Cl)(N(t)Bu)4py2(µ3-S)2(µ-S)2](C5H5) (M = Nb 11, Ta 12), also obtained by reaction of 5 and 6 with cyclopentadienyllithium in 1:3 ratio. As further evidence, 11 and 12 led to complexes 9 and 10 by treatment with one more equivalent of the lithium reagent. The structural study of these metal sulfide clusters has been also performed by X-ray crystallography.