Nitrate and nitroarene hydrogenations catalyzed by alkaline-earth nickel phosphide clathrates.

The alkaline-earth-containing nickel phosphide clathrates AeNi2P4 (Ae = Ba, Sr) are investigated as catalysts for the reduction of nitrate or nitroarenes in aqueous or ethanolic solution, respectively. While AeNi2P4 clathrates are inactive in their bulk polycrystalline form, they become active in nitrate hydrogenation after size reduction by either grinding or ball milling. However, while the clathrate structure remains intact after manual grinding, ball milling is of limited use as it results in significant clathrate degradation. Ground AeNi2P4 catalysts are also active in nitroarene hydrogenation. Condensation products such as azoxy- and azo-benzenes form early (4 h) but anilines accumulate after long reaction times (24 h). Unexpectedly, BaNi2P4 partially devinylates nitrostyrene to nitrobenzene. Overall, BaNi2P4 is more active than SrNi2P4 in both nitrate and nitroarene hydrogenation. These results showcase the potential utility of clathrates in a growing number of catalytic transformations.

Relativistic DFT Calculations of Cadmium and Selenium Solid-State NMR Spectra of CdSe Nanocrystal Surfaces.

Solid-state NMR spectra have been used to probe the structure of CdSe nanocrystals and propose detailed models of their surface structures. Density functional theory (DFT)-optimized cluster models that represent probable molecular structures of carboxylate-coordinated surface sites have been proposed. However, to the best of our knowledge, 113Cd and 77Se chemical shifts have not been calculated for these surface models. We performed relativistic DFT calculations of cadmium and selenium magnetic shielding tensors on model compounds with previously measured solid-state NMR spectra with (i) the four-component Dirac-Kohn-Sham (DKS) Hamiltonian and (ii) the scalar and (iii) spin-orbit levels within the ZORA Hamiltonian. Molecular clusters with Cd and Se sites in varying bonding environments were used to model CdSe (100) and CdSe(111) surfaces capped with carboxylic acid ligands. Our calculations identify the observed 113Cd isotropic chemical shifts δ(iso) of -465, -318, and -146 ppm arising from CdSeO3, CdSe2O2, and CdSe3O surface groups, respectively, with very good agreement with experimental measurements. The 113Cd chemical shifts linearly decrease with the number of O-neighbors. The calculated spans (δ11 - δ33) encompass the experimental values for CdSe3O and CdSe2O2 clusters but are slightly larger than the measured value for CdSeO3 clusters. Relativistic DFT calculations predicted a one-bond 113Cd-77Se scalar coupling of 258 Hz, which is in good agreement with the experimental values of 250 Hz. With a dense coverage of carboxylic acid ligands, the CdSe (100) surface shows a distribution of Cd-Se bond lengths and J-couplings. Relativistic DFT simulations thus aid in interpretation of NMR spectra of CdSe nanocrystals and related nanomaterials.

Case Report: Localized bullous pemphigoid induced by local triggers: a case series and a proposal for diagnostic criteria based on a literature review.

Introduction: Localized bullous pemphigoid (LBP) is an infrequent bullous pemphigoid (BP) variant restricted to a body region. According to the most compelling evidence, LBP occurs in patients with pre-existent serum antibodies against the basement membrane zone, which occasionally acquire the capacity to induce disease after the influence of different local factors acting as triggers. Methods: We hereby present a multicenter cohort of 7 patients with LBP developed after local triggers: radiotherapy, thermal burns, surgery, rosacea, edema and a paretic leg. In addition, we conducted a review of the literature, and we propose a set of diagnostic criteria for LBP, also based on our case series and the 2022 BP guidelines from the European Academy of Dermatology and Venereology. Results: During follow-up, three of the patients from our series evolved to a generalized BP, with only one requiring hospitalization. Our literature search retrieved 47 articles including a total of 108 patients with LBP, with a 63% with a potential local precipitating factor previous to their diagnosis. LBP mostly affected older females, and a subsequent generalized progression occurred in 16.7% of the cases. The most frequently involved areas were the lower limbs. Radiation therapy and surgery were responsible for the inducement of nearly 2 in 3 cases of LBP. We observed a significantly higher risk of generalization in cases where the trigger led to the developing of LBP earlier (p=0.016). Our statistical analysis did not detect any other prognosis factor for generalization when assessing direct immunofluorescence, histological and serological results, or other patient related factors. Conclusion: LBP should be suspected in patients with recurrent localized bullous eruptions. The presence of a trauma history in the same anatomic area is reported in most cases.

A new approach for the acquisition of trauma surgical skills: an OSCE type of simulation training program.

BACKGROUND: Worldwide, trauma-related deaths are one of the main causes of mortality. Appropriate surgical treatment is crucial to prevent mortality, however, in the past decade, general surgery residents' exposure to trauma cases has decreased, particularly since the COVID-19 pandemic. In this context, accessible simulation-based training scenarios are essential. METHODS: A low-cost, previously tested OSCE scenario for the evaluation of surgical skills in trauma was implemented as part of a short training boot camp for residents and recently graduated surgeons. The following stations were included bowel anastomosis, vascular anastomosis, penetrating lung injury, penetrating cardiac injury, and gastric perforation (laparoscopic suturing). A total of 75 participants from 15 different programs were recruited. Each station was videotaped in high definition and assessed in a remote and asynchronous manner. The level of competency was assessed through global and specific rating scales alongside procedural times. Self-confidence to perform the procedure as the leading surgeon was evaluated before and after training. RESULTS: Statistically significant differences were found in pre-training scores between groups for all stations. The lowest scores were obtained in the cardiac and lung injury stations. After training, participants significantly increased their level of competence in both grading systems. Procedural times for the pulmonary tractotomy, bowel anastomosis, and vascular anastomosis stations increased after training. A significant improvement in self-confidence was shown in all stations. CONCLUSION: An OSCE scenario for training surgical skills in trauma was effective in improving proficiency level and self-confidence. Low pre-training scores and level of confidence in the cardiac and lung injury stations represent a deficit in residency programs that should be addressed. The incorporation of simulation-based teaching tools at early stages in residency would be beneficial when future surgeons face extremely severe trauma scenarios.

Validity Argument for a Simulation-Based Objective Structured Clinical Examination Scenario for Evaluation of Surgical Skills in Trauma.

BACKGROUND: Trauma is one of the main causes of death globally, and appropriate surgical care is crucial to impact mortality. However, resident-performed trauma cases have diminished in the last 10 years. Simulation-based tools have proven to be effective to evaluate practical skills in a variety of settings. However, there is a lack of evidence regarding proper validation of trauma surgery models. OBJECTIVE: The aim of this study was to evaluate under a contemporary validity framework, an objective structured clinical evaluation (OSCE) scenario for the assessment of basic and advanced surgical skills in trauma and emergency surgery. METHODS: An OSCE-type simulation assessment program was developed incorporating six stations representing basic and advanced surgical skills that are essential in trauma surgery. Each station was designed using ex-vivo animal tissue. The stations included basic knots and sutures, bowel resection and anastomosis, vascular end-to-end anastomosis, lung injury repair, cardiac injury repair, and laparoscopic suturing. Eight postgraduate year 2 (PY-2), eight recently graduated surgeons (RGS), and 3 experts were recruited, and their performance was blindly assessed by experts using the validated general rating scale OSATS (Objective Structured Assessment of Technical Skills) as well as the time taken to complete the procedure. RESULTS: Significant differences were identified among groups. The average OSATS score was 82 for the PY2 group, 113 for the RGS group, and 147 for the experts (P < 0.01). The average procedural time to complete all the stations was 98 minutes for the PY2 group, 68 minutes for the RGS group, and 35 minutes for the expert surgeons (P < 0.01). CONCLUSION: An OSCE scenario designed using ex-vivo tissue met 4 out of 5 criteria of the Messick validity framework: content, relation to other variables, response process and consequences of the test. The results show it is a valid strategy for the evaluation of practical skills in trauma surgery.

Elaboración de un simulador de trauma torácico a partir de un torso cadavérico utilizando tecnología de imágenes digitales e impresión 3D / Elaboration of a thoracic trauma surgery simulation model from a cadaveric human torso incorporating digital image technology and 3D printing

Resumen Objetivo: Presentar la elaboración de un simulador de trauma torácico de alta fidelidad elaborado mediante modelamiento e impresión 3D a partir de un torso humano cadavérico. Materiales y Método: Estudio descriptivo del desarrollo de un simulador de trauma torácico utilizando metodología centrada en el prototipado y la iteración basada en testeos. Resultados: Se elaboró un simulador reutilizable mediante la digitalización de un torso cadavérico utilizando tomografía computada. Se realizó una reconstrucción digital del torso diseñando los planos subcutáneos, muscular y óseo en base a las imágenes del paciente pre y postoracotomía anterolateral. Utilizando impresión 3D y materiales sintéticos, se elaboró la caja torácica para luego instalar un corazón y pulmón porcino ventilado y perfundido. Los parches de la toracotomía son reemplazables y de bajo costo. En conjunto, este simulador permite el entrenamiento en manejo de lesiones traumáticas cardiacas y pulmonares de alta fidelidad. Conclusión: La metodología presentada permite la creación de un modelo para el entrenamiento y evaluación de habilidades quirúrgicas en trauma torácico. Los elementos principales del simulador son reutilizables y permiten mantener bajos los costos del entrenamiento.

Aim: To describe the design and creation of a high-fidelity thoracic trauma surgery simulation model incorporating 3D printing technology using a cadaveric human torso as a model. Materials and Method: This is a descriptive study that aims to illustrate the creation process of a thoracic trauma surgery simulation model throughout the incorporation of prototypes and dynamic iteration technologies. Results: A high-fidelity reusable thoracic trauma surgery simulation model was created from the digitalization of a cadaveric torso using a computed tomography scan. Throughout digital reconstruction tools, the subcutaneous, muscular, and skeletal structures were modeled from images obtained before and after an anterolateral thoracotomy. Using 3D printing and synthetic materials, a high-fidelity thoracic cavity was built so that perfused and ventilated porcine heart and lungs could be placed. A thoracotomy patch for the anterolateral thoracotomy was designed in a reusable and low-cost fashion. This simulation model is suitable for high fidelity training in the surgical management of cardiopulmonary traumatic injuries. Conclusion: The described methodology allowed the creation of a simulation model for training and assessment of surgical skills in thoracic trauma. The main components of the simulation model are made from reusable materials, broadening access to low-cost, high fidelity training.

SELF-CONFIDENCE ON ACQUIRED SURGICAL SKILLS TO DEAL WITH SEVERE TRAUMA PATIENTS IN RECENTLY GRADUATED SURGEONS.

BACKGROUND: Level of competence by procedure. Trauma is one of the leading causes of death in the world and proper surgical care is critical to impact mortality. In Chile, trauma associated death ranks first as mortality cause in population between 20 and 59 years old. Appropriate surgical skills are required to deal with these complex patients. Self-confidence to practice trauma procedures after the General Surgery Residency have not been reported in our country. AIM: Describe the level of self-confidence to deal with trauma procedures of surgeons who recently graduated from a General Surgery Residency. METHOD: Descriptive cross-sectional study. We designed and applied a survey in 2015, 2016 and 2017 to recently graduated surgeons, to inquire about self-confidence of surgical skills to deal with trauma scenarios. Eighteen trauma surgery procedures (including cervical, thoracic, abdominal and vascular procedures) were evaluated using a 5-grade Likert scale. The number of procedures performed during the residency was also queried. RESULTS: Eighty-eight recently graduated surgeons from 11 different training programs in Chile were included. The report of competencies was high in procedures such as intestinal injuries, were 98% felt competent or very competent in their repair. On the other hand, in complex traumas such as major vessel injury, up to 76% reported not being competent. Self-confidence on procedures was directly associated with the number of procedures performed during residency. CONCLUSIONS: Recently graduated surgeons from General Surgery Programs report high levels of confidence to deal with low and intermediate complexity traumas, but a lower level of confidence to treat high complexity cases.

Self-confidence on acquired surgical skills to deal with severe trauma patients in recently graduated surgeons / Autoconfiança nas habilidades cirúrgicas adquiridas para lidar com pacientes com trauma grave em cirurgiões recém-formados

ABSTRACT Background: Trauma is one of the leading causes of death in the world and proper surgical care is critical to impact mortality. In Chile, trauma associated death ranks first as mortality cause in population between 20 and 59 years old. Appropriate surgical skills are required to deal with these complex patients. Self-confidence to practice trauma procedures after the General Surgery Residency have not been reported in our country. Aim: Describe the level of self-confidence to deal with trauma procedures of surgeons who recently graduated from a General Surgery Residency. Method: Descriptive cross-sectional study. We designed and applied a survey in 2015, 2016 and 2017 to recently graduated surgeons, to inquire about self-confidence of surgical skills to deal with trauma scenarios. Eighteen trauma surgery procedures (including cervical, thoracic, abdominal and vascular procedures) were evaluated using a 5-grade Likert scale. The number of procedures performed during the residency was also queried. Results: Eighty-eight recently graduated surgeons from 11 different training programs in Chile were included. The report of competencies was high in procedures such as intestinal injuries, were 98% felt competent or very competent in their repair. On the other hand, in complex traumas such as major vessel injury, up to 76% reported not being competent. Self-confidence on procedures was directly associated with the number of procedures performed during residency. Conclusions: Recently graduated surgeons from General Surgery Programs report high levels of confidence to deal with low and intermediate complexity traumas, but a lower level of confidence to treat high complexity cases.

RESUMO Racional: Trauma é uma das principais causas de morte no mundo e cuidados cirúrgicos adequados são críticos para determinar a mortalidade. No Chile, morte associada a trauma é a primeira causa de mortalidade na população entre 20 e 59 anos. Para lidar com esses pacientes complexos, são necessárias habilidades cirúrgicas precisas para esses procedimentos. Autoconfiança de cirurgiões recentemente graduados na Residência em Cirurgia Geral para práticas de procedimentos de trauma no nosso país não tem sido reportada. Objetivo: Descrever nível de autoconfiança para lidar com procedimentos de trauma em cirurgiões recentemente graduados na residência de cirurgia geral. Método: Estudo transversal. Foi desenhada e aplicada uma enquete em 2015, 2016 e 2017 a cirurgiões recentemente graduados para pesquisar sobre autoconfiança e habilidades cirúrgicas para lidar com cenários de trauma. Foram avaliados 18 procedimentos cirúrgicos de trauma (incluindo procedimentos cervicais, torácicos, abdominais e vasculares) usando a 5-grade Likert Scale. O número total de procedimentos feitos durante a residência foi avaliado. Resultados: Foram incluídos 88 cirurgiões recentemente graduados. O nível de competência foi reportado como alto em procedimentos como trauma intestinal, onde 98% sentiu-se competente ou muito competente em sua reparação. Por outro lado, em traumas complexos como dano vascular maior, até 76% reportaram não se sentirem competentes. A autoconfiança nos procedimentos esteve diretamente associada com o número de procedimentos realizados. Conclusões: Cirurgiões recentemente graduados na residência de cirurgia geral reportam níveis altos de confiança para lidar com traumas de complexidade baixa e média, mas um nível menor de confiança para tratar casos de complexidade alta.

Iron and Cobalt Diazoalkane Complexes Supported by ß-Diketiminate Ligands: A Synthetic, Spectroscopic, and Computational Investigation.

Diazoalkanes are interesting redox-active ligands and also precursors to carbene fragments. We describe a systematic study of the binding and electronic structure of diphenyldiazomethane complexes of ß-diketiminate supported iron and cobalt, which span a range of formal d-electron counts of 7-9. In end-on diazoalkane complexes of formally monovalent three-coordinate transition metals, the electronic structures are best described as having the metal in the +2 oxidation state with an antiferromagnetically coupled radical anion diazoalkane as shown by crystallography, spectroscopy, and computations. A formally zerovalent cobalt complex has different structures depending on whether potassium binds; potassium binding gives transfer of two electrons into the η2-diazoalkane, but the removal of the potassium with crown ether leads to a form with only one electron transferred into an η1-diazoalkane. These results demonstrate the influence of potassium binding and metal oxidation state on the charge localization in the diazoalkane complexes. Interestingly, none of these reduced complexes yield carbene fragments, but the new cobalt(II) complex LtBuCoPF6 (LtBu = bulky ß-diketiminate) does catalyze the formation of an azine from its cognate diazoalkane, suggesting N2 loss and transient carbene formation.

Hábitos alimentarios y funcionalidad familiar en familias de la región metropolitana: un estudio descriptivo / Eating habits and family functionality in families in the metropolitan region: A descriptive study

Existen múltiples estudios acerca del funcionamiento familiar en la población chilena y sobre sus prácticas alimenticias, relacionándose ambas con morbilidades psicológicas o psiquiátricas. A pesar de esto, no logramos encontrar estudios que relacionen específicamente los hábitos alimenticios con el comportamiento a la hora de comer y el funcionamiento familiar en Chile. Definir los hábitos alimentarios no resulta sencillo, ya que existe una diversidad de conceptos, sin embargo, la mayoría converge en que se tratan de manifestaciones recurrentes de comportamiento individuales y colectivas respecto al qué, cuándo, dónde, cómo, con qué, para qué se come y quién consume los alimentos (1). El presente estudio es un estudio descriptivo tipo corte transversal, cuyo objetivo es explorar la relación entre el funcionamiento familiar y el hábito de comer en familia en padres y madres que acuden al policlínico de pediatría. El estudio se aplicó en 5 centros de salud de diferentes comunas de la región Metropolitana: Centro de Salud de San Bernardo (San Bernardo), Policlínico el Salto (Recoleta), Patronato Nacional de la Infancia (Estación central), CESFAM Juan Pablo II (La Reina) y CESFAM Aníbal Ariztía (Las Condes). Todos corresponden a campos clínicos universitarios de la Universidad de Los Andes en el área de pediatría. Todos centros caracterizados por recibir pacientes en su mayoría chilenos, de un nivel socioeconómico medio-bajo (2). Se consideraron como criterios de inclusión el ser padres y/o madres de pacientes que se atendían en los consultorios antes mencionados, mayores de 18 años y que firmaran el consentimiento informado. Los datos fueron obtenidos mediante la auto-aplicación de dos cuestionarios, uno de ellos, de fabricación propia, describe la práctica alimenticia de la familia, el otro, correspondiente al cuestionario APGAR familiar, validado en Chile, fue usado para medir el funcionamiento familiar según la percepción de los padres y/o madres. De un total de 53 encuestas realizadas, 90.6% presentó un APGAR de familia funcional, un 7.5% un APGAR con disfunción familiar moderada y un 1.88% con un APGAR de disfunción familiar severa. El análisis estadístico muestra que este nivel de funcionamiento se explica en un 53% por tres de las variables estudiadas; Comunicación y ambiente a la hora de comer, y si los padres viven juntos o no. Será necesario confirmar estos hallazgos en futuras investigaciones que cuenten con poblaciones de estudio más extensas y variadas en su morfología familiar, para extrapolar estos datos a nivel regional. Palabras clave: APGAR, funcionamiento familiar, comer en familia, hábito alimenticio, trastornos alimenticios

Abstract: There are multiple studies on family functioning in the Chilean population and on their dietary practices, both have been related to psychological or psychiatric morbidities. Despite this, we could not find studies that specifically relate eating habits to eating behaviors and family functioning in Chile. Defining eating habits is not easy, since there is a diversity of concepts, however, most converge in that they are recurrent manifestations of individual and collective behavior with respect to what, when, where, how, with what, and for what purpose we eat and who consumes the food (1). The present study is a descriptive cross-sectional study, whose objective is to explore the relationship between family functioning and the habit of eating as a family in parents who attend the pediatric polyclinic. The study was performed in 5 health centers in different communes of the Metropolitan Region: San Bernardo Health Center (San Bernardo), El Salto Polyclinic (Recoleta), National Children's Trust (Central Station), CESFAM Juan Pablo II (La Reina) and CESFAM Aníbal Ariztía (Las Condes). All correspond to pediatric university clinical campuses of the Universidad de Los Andes. All centers are characterized as receiving mostly Chilean patients, of a medium-low socioeconomic level (2). Inclusion criteria were: fathers and/or mothers of patients who attended the clinics, who were older than 18 years and who signed the informed consent. The data were obtained through the self-administration of two questionnaires, one of them of our own manufacture, describes the family's nutritional practice, the other, corresponding to the family APGAR questionnaire, validated in Chile, was used to measure family functioning according to the perception of fathers and/or mothers. Of a total of 53 surveys conducted, 90.6% presented an APGAR of functional family, 7.5% an APGAR with moderate family dysfunction and 1.88% with an APGAR of severe family dysfunction. The statistical analysis shows that this level of functioning is explained in 53% by three of the studied variables: communication and atmosphere at mealtime, and whether the parents live together or not. It will be necessary to confirm these findings in future investigations that have more extensive and varied study populations in their family morphology to extrapolate these data at a regional level.Key words: APGAR, family functionality, family meal, feeding behavior, eating disorders

Multishell Au/Ag/SiO2 nanorods with tunable optical properties as single particle orientation and rotational tracking probes.

Three-layer core-shell plasmonic nanorods (Au/Ag/SiO2-NRs), consisting of a gold nanorod core, a thin silver shell, and a thin silica layer, were synthesized and used as optical imaging probes under a differential interference contrast microscope for single particle orientation and rotational tracking. The localized surface plasmon resonance modes were enhanced upon the addition of the silver shell, and the anisotropic optical properties of gold nanorods were maintained. The silica coating enables surface functionalization with silane coupling agents and provides enhanced stability and biocompatibility. Taking advantage of the longitudinal LSPR enhancement, the orientation and rotational information of the hybrid nanorods on synthetic lipid bilayers and on live cell membranes were obtained with millisecond temporal resolution using a scientific complementary metal-oxide-semiconductor camera. The results demonstrate that the as-synthesized hybrid nanorods are promising imaging probes with improved sensitivity and good biocompatibility for single plasmonic particle tracking experiments in biological systems.

Characterization of polyhormonal insulin-producing cells derived in vitro from human embryonic stem cells.

Human embryonic stem cells (hESCs) were used as a model system of human pancreas development to study characteristics of the polyhormonal cells that arise during fetal pancreas development. HESCs were differentiated into fetal-like pancreatic cells in vitro using a 33-day, 7-stage protocol. Cultures were ~90-95% PDX1-positive by day (d) 11 and 70-75% NKX6.1-positive by d17. Polyhormonal cells were scattered at d17, but developed into islet-like clusters that expressed key transcription factors by d33. Human C-peptide and glucagon secretion were first detected at d17 and increased thereafter in parallel with INS and GCG transcript levels. HESC-derived cells were responsive to KCl and arginine, but not glucose in perifusion studies. Compared to adult human islets, hESC-derived cells expressed ~10-fold higher levels of glucose transporter 1 (GLUT1) mRNA, but similar levels of glucokinase (GCK). In situ hybridization confirmed the presence of GLUT1 transcript within endocrine cells. However, GLUT1 protein was excluded from this population and was instead observed predominantly in non-endocrine cells, whereas GCK was co-expressed in insulin-positive cells. In rubidium efflux assays, hESC-derived cells displayed mild potassium channel activity, but no responsiveness to glucose, metabolic inhibitors or glibenclamide. Western blotting experiments revealed that the higher molecular weight SUR1 band was absent in hESC-derived cells, suggesting a lack of functional KATP channels at the cell surface. In addition, KATP channel subunit transcript levels were not at a 1:1 ratio, as would be expected (SUR1 levels were ~5-fold lower than KIR6.2). Various ratios of SUR1:KIR6.2 plasmids were transfected into COSM6 cells and rubidium efflux was found to be particularly sensitive to a reduction in SUR1. These data suggest that an impaired ratio of SUR1:KIR6.2 may contribute to the observed KATP channel defects in hESC-derived islet endocrine cells, and along with lack of GLUT1, may explain the absence of glucose-stimulated insulin secretion.

Clinical outcomes of minimally invasive versus open approach for one-level transforaminal lumbar interbody fusion at the 3- to 4-year follow-up.

PURPOSE: Supporters of minimally invasive approaches for transforaminal lumbar interbody fusion (TLIF) have reported short-term advantages associated with a reduced soft tissue trauma. Nevertheless, mid- and long-term outcomes and specifically those involving physical activities have not been adequately studied. The aim of this study was to compare the clinical outcomes of mini-open versus classic open surgery for one-level TLIF, with an individualized evaluation of the variables used for the clinical assessment. METHODS: A prospective cohort study was conducted of 41 individuals with degenerative disc disease who underwent a one-level TLIF from January 2007 to June 2008. Patients were randomized into two groups depending on the type of surgery performed: classic open (CL-TLIF) group and mini-open approach (MO-TLIF) group. The visual analog scale (VAS), North American Spine Society (NASS) Low Back Pain Outcome instrument, Oswestry Disability Index (ODI) and the Short Form 36 Health Survey (SF-36) were used for clinical assessment in a minimum 3-year follow-up (36-54 months). RESULTS: Patients of the MO-TLIF group presented lower rates of lumbar (p = 0.194) and sciatic pain (p = 0.427) and performed better in daily life activities, especially in those requiring mild efforts: lifting slight weights (p = 0.081), standing (p = 0.097), carrying groceries (p = 0.033), walking (p = 0.069) and dressing (p = 0.074). Nevertheless, the global scores of the clinical questionnaires showed no statistical differences between the CL-TLIF and the MO-TLIF groups. CONCLUSIONS: Despite an improved functional status of MO-TLIF patients in the short term, the clinical outcomes of mini-open TLIF at the 3- to 4-year follow-up showed no clinically relevant differences to those obtained with open TLIF.

Quantitative geometric descriptions of the belt iron atoms of the iron-molybdenum cofactor of nitrogenase and synthetic iron(II) model complexes.

Six of the seven iron atoms in the iron-molybdenum cofactor of nitrogenase display an unusual geometry, which is distorted from the tetrahedral geometry that is most common in iron-sulfur clusters. This distortion pulls the iron along one C3 axis of the tetrahedron toward a trigonal pyramid. The trigonal pyramidal coordination geometry is rare in four-coordinate transition metal complexes. In order to document this geometry in a systematic fashion in iron(II) chemistry, we have synthesized a range of four-coordinate iron(II) complexes that vary from tetrahedral to trigonal pyramidal. Continuous shape measures are used for a quantitative comparison of the stereochemistry of the Fe atoms in the iron-molybdenum cofactor with those of the presently and previously reported model complexes, as well as with those in polynuclear iron-sulfur compounds. This understanding of the iron coordination geometry is expected to assist in the design of synthetic analogues for intermediates in the nitrogenase catalytic cycle.

Macrocyclic Binucleating ß-Diketiminate Ligands and their Lithium, Aluminum, and Zinc Complexes.

The incorporation of rigid aromatic linkers into ß-diketiminate ligands creates a binucleating scaffold that holds two metals near each other. This paper discloses the synthesis, characterization, and reactivity of mBin(2-), which has a meta-substituted xylylene spacer, and pBin(2-), which has a para-substituted xylylene spacer. Lithium, aluminum, and zinc complexes of each ligand are isolated, and in some cases are characterized by X-ray crystallography. The lithium complexes are coordinated to solvent-derived THF ligands, while the zinc and aluminum complexes have alkyl ligands. Complexes of the mBin(2-) ligand have an anti conformation in which the metals are on opposite sides of the macrocycle, while pBin(2-) complexes prefer a syn conformation. The (1)H NMR spectra of the complexes demonstrate that the conformations rapidly interconvert in the lithium complexes, and less rapidly in the zinc and aluminum complexes.