Effect of the degree of oxidation of graphene oxide on As(III) adsorption.

The study of the interaction between graphene oxide (GO) and arsenic is of great relevance not only in the design of adsorbent materials to remove this contaminant but also in the understanding of its combined nanotoxicity. In this work, we show that As(III) adsorption, primarily H3AsO3, by graphene oxide is affected by its degree of oxidation. Three types of GO with C/O ratios between 1.35 and 1.98 were produced, resulting in important variations in the concentration of COH and COC functional groups. The less oxidized material reached a maximum As(III) adsorption capacity of 123 mg/g, whereas the GO with the highest degree of oxidation reached a value of 288 mg/g at pH 7, the highest reported in the literature. We also show that sulfates and carbonates present in water strongly inhibit As(III) adsorption. The interaction between graphene oxide and As(III) was also studied by Density Functional Theory (DFT) computer models showing that graphene oxide interacts with As(III) primarily through hydrogen bonds, having interaction energies with the hydroxyl and epoxide groups of 1508.6 and 1583.6 kJ/mol, respectively. Finally, cytotoxicity tests showed that the graphene oxide maintained cellular viability of 57% with 50 µg/ml, regardless of its degree of oxidation.

Esplenectomía laparoscópica en pacientes con púrpura trombocitopénica idiopática: primera experiencia en el Hospital Regional de Arica / Laparoscopic splenectomy in patients with idiopathic thrombocytopenic purpura: first experience at the Regional Hospital of Arica

Introducción: La púrpura trombocitopénica idiopática (PTI) es una de las trombocitopenias más frecuentes en adultos. La esplenectomía corresponde a uno de sus tratamientos de segunda línea en pacientes refractarios a otras terapias médicas. Objetivo: Presentar nuestra primera experiencia en esplenectomía laparoscópica en el servicio de cirugía del Hospital Regional de Arica. Materiales y métodos: Se realizó una revisión transversal retrospectiva de pacientes con PTI a quienes se les indicó esplenectomía por falla en el tratamiento médico. Se tabularon los exámenes preoperatorios, plaquetas 24 h pre y posquirúrgicas, plaquetas al inicio del estudio (3 meses preoperatorios) y al mes del postoperatorio, complicaciones quirúrgicas y características histopatológicas. Resultados: Se realizaron 5 esplenectomías. El 100% de los pacientes presentaron mejoría a las 24 h de postoperados. Al cabo de un mes, sólo 3 de 5 pacientes tuvieron una mejoría de su trombocitopenia. No hubo complicaciones mayores como hemoperitoneo o fístulas pancreáticas. Un paciente presentó equimosis en un puerto. Conclusiones: La esplenectomía laparoscópica es una técnica factible de realizar en nuestro centro, con una tasa de complicaciones y resultados comparables con centros de mayor volumen.

Introduction: Idiopathic thrombocytopenic purpura (ITP) is one of the most common acquired thrombocytopenia in adults. Splenectomy is as second line treatment in medical refractory patients. Aim: The aim of this study is to present our first initial experience in laparoscopic splenectomy of the surgical department of Arica's local hospital. Materials and methods: This is a transversal prospective review of patients with ITP which splenectomy was performed due medical treatment failure. Preoperative blood test: platelet count at the beginning of the study, 24 h pre op, 24 h post op and a month post surgery were tabulated. Postoperative complications and histopathology characteristics were reported. Results: We performed 5 splenectomies, 100% of the patients presented a recovery platelet count at 24 h postop. In the first month only 3 patients had an improvement of their thrombocytopenia. There were no major complications, like hemoperitoneum or pancreatic leaks, only one patient presented port site ecchymosis. Conclusions: Laparoscopic splenectomy is a feasible technique in our center with a complication rate and outcomes comparable to high volume center.

Could monopronucleated ICSI zygotes be considered for transfer? Analysis through time-lapse monitoring and PGS.

PURPOSE: The purpose of this study was to investigate the chromosomal constitution and the developmental potential of intracytoplasmic sperm injection (ICSI) deriving embryos displaying a single pronucleus at the zygote stage. METHODS: Eighty-eight embryos from single pronucleus (1PN) two polar bodies (2PB) ICSI zygotes from 64 preimplantational genetic screening (PGS) cycles (October 2012-December 2014), were retrospectively analyzed. Zygotes were cultured in a time-lapse incubator. Embryo biopsy was performed on day 3 and genetic analysis approached by array comparative genomic hybridization. RESULTS: Chromosomal analysis revealed that 17% (15/88) of embryos derived from 1PN 2PB zygotes were diagnosed as euploid. After blastomere biopsy at day 3, the blastocyst rate at day 5 was 3.4% (3/88). Only 2.3% (2/88) euploid blastocysts were obtained. In two couples and after counseling and patient agreement, the transfer of a euploid blastocyst from a 1PN 2PB ICSI zygote was performed resulting in the birth of a healthy child. CONCLUSIONS: These results open the possibility to consider embryos coming from 1PN 2PB ICSI zygotes for transfer when no other embryos from 2PN 2PB ICSI zygotes are available and if a PGS diagnosis of euploidy is obtained. Confirmation of biparental inheritance is strongly recommended.

Agenesia del lóbulo hepático derecho asociado a agenesia vesicular / Agenesis of the right hepatic lobe associated with gallbladder agenesis

Background: Anatomical abnormalities of the liver are rare and their association with gallbladder agenesis are even more uncommon. Case report: We report a 63 years old man complaining of jaundice, without pain or fever. A magnetic resonance imaging showed a right hepatic lobe agenesis associated with gallbladder agenesis. Jaundice subsided spontaneously.

Introducción: Las anomalías anatómicas del hígado son raras, la asociación a una agenesia vesicular es más infrecuente aún, siendo su diagnóstico generalmente un hallazgo. Caso clínico: Presentamos el caso de un paciente masculino de 63 años que consulta por ictericia, sin dolor ni fiebre, al cual se le realiza diagnóstico por imagen con resonancia magnética de agenesia de lóbulo hepático derecho asociado a agenesia vesicular. Dado que el paciente no tiene litiasis biliar, se decide tratamiento médico.

Electrical and optical properties of copper and nickel molecular materials with tetrabenzo [b,f,j,n] [1,5,9,13] tetraazacyclohexadecine thin films grown by the vacuum thermal evaporation technique.

Semiconducting molecular-material thin-films of tetrabenzo (b,f,j,n) [1,5,9,13] tetraazacyclohexadecine copper(II) and nickel(II) bisanthraflavates have been prepared by using vacuum thermal evaporation on Corning glass substrates and crystalline silicon wafers. The films thus obtained were characterized by infrared spectroscopy (FTIR), atomic force microscopy (AFM), ultraviolet-visible (UV-vis) spectroscopy and ellipsometry. IR spectroscopy showed that the molecular-material thin-films exhibit the same intra-molecular bonds as the original compounds, which suggests that the thermal evaporation process does not significantly alter their bonds. The optical band-gap values calculated from the absorption coefficient may be related to non-direct electronic interband transitions. The effect of temperature on conductivity was also measured in these samples. It was found that the temperature-dependent electric current is always higher for the nickel-based material and suggests a semiconductor-like behavior with conductivities in the order of 10(-8)Omega(-1)cm(-1).

Patterns of recurrence and survival in breast cancer.

Breast cancer is the leading cause of death affecting women worldwide, according to mortality estimation and incidence. In Chile, breast cancer ranks third among cancer mortality rates. Two-hundred and eighty-three breast cancer patients registered at the Gustavo Fricke Hospital of Viña del Mar, Chile, were studied to assess the influence of several factors on the recurrence and survival of breast cancer patients. Patients selected had 5-year post-surgery recurrences of breast cancer and had an average of 58.5 years of age. The variables considered in these patients were the quadrants involved, stage of the tumor, type of recurrence, type of exams, type of surgery, the grade of tumor in relation to Broder's classification and pathology of tumor. The results indicated that the superior external right and left quadrants, Stage IIA, loco-regional recurrences, lumpectomies with axillar lymph node removal and after 5 years, Grade II were prevalent in this population. Among the pathologies analyzed, the ductal carcinomas were the most commonly found and were positive for PCNA, beta-catenin, cytokeratin 18 and ErbB2 protein expression. A median follow-up of 60 months of survival was achieved in 95% of patients. However, those cases with a recurrence of breast cancer had only 40% survival. The risk of mortality was significantly greater when recurrence was present (P<0.0001). The global probability of survival of the patients reached 72% after 5 years. It can be concluded that early detection of breast cancer allows for control of the disease and avoids remissions, or at least extends survival.

Fractura de húmero por medición de fuerzas o gallitos: reporte de casos / Humeral fracture during arm wrestling: case reports

Humeral fracture during arm wrestling is unusual. There are not many cases described. Demographical characteristics and mechanism seems to be a common factor. Frequently, correspond to a distal third humeral shaft spiral fracture. Some cases can be associated to a radial nerve injury. We present 2 cases which shown similar fractures, one of them with radial nerve palsy. Both cases underwent to open reduction and internal fixation.

La fractura de húmero por medición de fuerzas o “gallitos”, es un evento inusual. Los reportes bibliográficos son escasos. Las características demográficas y el mecanismo parecieran ser un factor común en todos los casos. Generalmente, corresponde a una fractura de tercio distal de diáfisis humeral de rasgo espiroideo. En algunas ocasiones se puede asociar a compromiso del nervio radial. Mostramos2 casos, los cuales presentan fracturas de similares características y uno de ellos compromiso del nervio radial. La resolución de ambos casos fue quirúrgica.

Prevalencia de diabetes tipo 2 y obesidad en dos poblaciones aborígenes de Chile en ambiente urbano / Prevalence of type 2 diabetes and obesity in two Chilean aboriginal populations living in urban zones

BACKGROUND: The prevalence of cardiovascular risk factors is increasing in aboriginal populations in Chile. AIM: To study the prevalence of obesity, type 2 diabetes and serum lipids in two aboriginal populations, Mapuche and Aymara, that were transferred from a rural to a urban environment. SUBJECTS AND METHODS: Two groups of subjects over 20 years were analyzed, Mapuche and Aymara. The Mapuche group was formed by 42 men and 105 women, living in four urban communities of Santiago, and an Aymara group formed by 42 men and 118 women, living in Arica, in Northern Chile. Anthropometric measurements, blood pressure, lipid profile, oral glucose tolerance test, fasting insulin and serum leptin were determined. RESULTS: The prevalence of type 2 diabetes was 6.9% in Aymara and 8.2% in Mapuche subjects. The frequency of glucose intolerance was similar in both groups, but greater among men. A total blood cholesterol over 200 mg/dl was observed in 43.1% of Aymara and 27.9% of Mapuche subjects (p <0.008). Serum triglycerides over 150 mg/dl were observed in 16.9 and 23.1% of Aymara and Mapuche individuals, respectively (p= NS). CONCLUSIONS: The prevalence of type 2 diabetes and dyslipidemia in turban aboriginal populations is higher than that of their rural counterparts. A possible explanation for these results are changes in lifestyles that come along with urbanization, characterized by a high consumption of saturated fat and refined sugars and a low level of physical activity.

Characterization of sugar mixtures utilization by an Escherichia coli mutant devoid of the phosphotransferase system.

Due to catabolite repression in microorganisms, sugar mixtures cannot be metabolized in a rapid and efficient manner. Therefore, the development of mutant strains that avoid this regulatory system is of special interest to fermentation processes. In the present study, the utilization of sugar mixtures by an Escherichia coli mutant strain devoid of the phosphotransferase system (PTS) was characterized. This mutant can transport glucose (PTS- Glucose+ phenotype) by a non-PTS mechanism as rapidly as its wild-type parental strain. In cultures grown in minimal medium supplemented with glucose-xylose or glucose-arabinose mixtures, glucose repressed arabinose- or xylose-utilization in the wild-type strain. However, under the same culture conditions with the PTS- Glucose+ mutant, glucose and arabinose were co-metabolized, but glucose still exerted a partial repressive effect on xylose consumption. In cultures growing with a triple mixture of glucose-arabinose-xylose, the wild-type strain sequentially utilized glucose, arabinose and finally, xylose. In contrast, the PTS- Glucose+ strain co-metabolized glucose and arabinose, whereas xylose was utilized after glucose-arabinose depletion. As a result of glucose-arabinose co-metabolism, the PTS- Glucose+ strain consumed the total amount of sugars contained in the culture medium 16% faster than the wild-type strain. [14C]-Xylose uptake experiments showed that in the PTS- Glucose+ strain, galactose permease increases xylose transport capacity and the observed partial repression of xylose utilization depends on the presence of intracellular glucose.

Formation of a novel trinuclear spirostannoxane tin(IV) compound. Crystal and molecular structure of [Sn(nBu)(Cl)[(OCH2CH2S)2Sn(nBu)]2] and the stannolane [(nBu)Sn(SCH2CH2O)SCH2CH2OH].

The reaction of nBuSnCl3 and the sodium salt of 2-mercaptoethanol (1:1) in ethanol gave the compound Sn(nBu)(Cl)[(OCH2CH2S)2Sn(nBu)]2 (1). [(nBu)Sn(SCH2CH2O)SCH2CH2OH] (2) was initially isolated from the reaction of 1 with nBuMgCl as a rearrangement product but was also synthesized from nBuSn(O)OH and two molar equivalents of 2-mercaptoethanol. Both compounds were characterized by means of IR, 119Sn, 13C, and 1H NMR, FAB mass spectroscopy, and elemental analyses. The structures were determined by single-crystal X-ray diffraction. 1 crystallizes in the monoclinic Cc space group (a = 18.492(3) A, b = 17.329(2) A, c = 10.787(1) A, beta = 111.88(1) degrees, Z = 4), while 2 crystallizes in the orthorhombic Pbca space group (a = 14.458(2) A, b = 10.393(1) A, c = 16.479(2) A, Z = 8). 1 is a trimetallic Tin(IV) compound in which the central atom is in 6-fold coordination, while the two remaining tin atoms show 5-fold coordination. Both pentacoordinated tin atoms are bonded to a butyl group and to the oxygen and the sulfur atoms from two [OCH2CH2S]2- ligands forming two stannolanes, which are fused with the hexacoordinated tin atom forming a distannoxane system. This arrangement is quite different from previous ladder or staircase structures. NMR data point to maintenance of this structure in solution. 2 consists of [(nBu)Sn(SCH2CH2O)(SCH2CH2OH)] units, which are associated via intermolecular Sn-O interactions building up a dimer. The tin atom forms two "stannolane" units by interaction with [OCH2CH2S]2- and [HOCH2CH2S]- ligands.

Sistema Kidd en la población aymara / Kidd system in aymara population

Los grupos sanguíneos constituyen una buena forma de medir factores genéticos en una población habiéndose demostrado una gran variabilidad en los diferentes grupos étnicos a nivel mundial. El sistema Kidd, en primera instancia, fue un sistema sencillo de dos antígenos, Jka y Jkb. El descubrimiento del poco frecuente fenotipo Jk(a-b), también conocido como fenotipo Hawai, llevó a postular la existencia de un tercer gen, Jk. Los anticuerpos de este sistema son el Anti-Jka y el Anti-Jkb. En este trabajo se estudió el el sistema Kidd en la población aymara, grupo étnico que habita en el sector andino de la I Región de Chile. La muestra consistió en 200 individuos aymaras de ambos sexos. Los antígenos del sistema Kidd fueron determinados mediante el método de antiglobulina indirecta, con anti Jkb y anti Jkb comerciales. Las frecuencias génicas encontradas fueron: Jka(p)=0.182; Jkb(q)=0.660 y Jk(r)=0.158. Los resultados obtenidos en la población aymara, muestran una gran diferencia en las frecuencias génicas, al ser comparadas con las reportadas para la raza blanca, en la cual no está descrita la existencia del gen Jk