Understanding the role of carboxylic acid surfactants in the growth inhibition effect during area-selective atomic layer deposition: the case of ZnO growth on Cu and Cu2O.

Herein, we report a detailed adsorption process of acetic acid (AA) as a model for the head group of carboxylic acid self-assembled monolayers on Cu and Cu2O (111) surfaces and the effect of diethyl zinc (DEZ) on its adsorption geometry on Cu2O (111) using quantum chemical calculations. The most stable adsorption configurations were obtained considering electrostatic potential compatibility from the molecule and surface. Overall, the adsorption behavior revealed bidentate binding as the most stable configuration. Weak van der Waals interactions are key in AA adsorption on Cu (111), while in Cu2O (111), coordination and hydrogen bonds dominated the interaction. AA adsorption geometry on Cu2O revealed that DEZ has no significative impact on the carbonyl-chemisorbed AA and bidentate adsorption modes. These results highlight the significance of the different adsorption modes for achieving area-selective deposition using atomic layer deposition and soft removal SAM molecules.

High-resolution esophageal manometry in a Mexican population: diagnostic outcome.

High-resolution esophageal manometry (HREM) has become the method of choice for evaluation of esophageal motility disorders. There is a paucity of data with this technique from Hispanic countries. This study aims to characterize the diagnostic outcome of HREM in a large cohort of consecutive patients in Mexico.This study was conducted in Monterrey, Mexico from March 1, 2013 to March 31, 2015. Our diverse study population included patients from a major academic institution and the community. HREM was done applying the Chicago Classification 3. Diagnostic outcome was grouped as weak peristaltic disorders, gastroesophageal junction disorders, and hypertensive/uncoordinated peristalsis.We studied 670 consecutive patients, 57% were women, mean age was 43.8 years. The majority (465 [69%]) were referred for preoperative evaluation of gastroesophageal reflux disease (GERD), 365 (78%) of whom had a normal study. Overall, 193 (29%) patients had abnormal motility, the most common disorder being weak peristalsis (104 [54%]). In patients with dysphagia, the most frequent finding was achalasia (23/46 [50%]).To our knowledge, this is the first study to characterize the diagnostic outcome of HREM in a large cohort of Hispanic patients in Latin America. At our open access center, 69% of patients were referred for preoperative evaluation of GERD, reflecting the popularity of antireflux surgery. This study confirms the high prevalence of weak peristalsis and highlights the importance of addressing its pathophysiology and management. The finding of achalasia in 50% of our patients with dysphagia is consistent with recent reports regarding the rising incidence of this disorder and underscores the need of prompt motility testing in this population.

Ab initio study of several static and dynamic properties of bulk liquid Ni near melting.

Several static and dynamic properties of bulk liquid Ni at a thermodynamic state near its triple point have been evaluated by ab initio molecular dynamics simulations. The calculated static structure shows very good agreement with the available experimental data, including an asymmetric second peak in the static structure factor, which underlines a marked local icosahedral short-range order in the liquid. The dynamical structure reveals propagating density fluctuations, and the calculated dynamic structure factors, S(q,ω), show a good agreement with the inelastic x-ray scattering measurements. The obtained dispersion relation closely follows that obtained from the inelastic x-ray scattering measurements; moreover we analyze the possible reasons behind its discrepancy with respect to the dispersion relation derived from the inelastic neutron scattering data. The dynamical processes behind the S(q,ω) have been analyzed by using a model with two decay channels (a fast and a slow) associated with the relaxations of the collective excitations. We have found that the transverse current spectral functions exhibit some features which, so far, had previously been shown by high pressure liquid metals only. Furthermore, the calculated S(q,ω) show, within some q-range, the appearance of transverse-like excitation modes, similar to those recently found in other liquid metals. Finally, results are also reported for several transport coefficients.

Mushrooms to live or die: toxicity of some Basidiomycota using Artemia franciscana.

Consumption of wild mushrooms has increased in recent years; however, not all of them are edible and there is no precise information on those that may cause poisoning. Therefore, studies to obtain data about their toxicity are needed. For this purpose, we used the brine shrimp Artemia franciscana, a crustacean employed in toxicity tests and with wide application in the toxin detection, including mycotoxins. Mushrooms were collected in the state of Jalisco, Mexico, with which aqueous extracts were prepared. Dilutions of the stock solution of each extract were made to final concentrations of 50, 100, 250, 500, and 1000 µg/mL. Potassium dichromate (PD) was used as positive control and artificial seawater as negative control. The median lethal dose (LD50) of extracts on nauplii of A. franciscana was calculated. The aqueous extracts obtained from Amanita amerivirosa, A. muscaria, Chlorophyllum molybdites, and Leucopaxillus amarus showed a LD50 < 70 µg/mL, similar to PD (LD50 = 37 µg/mL). This is the first indication of the probable toxicity of Leucopaxillus amarus in humans. Cantharellus cibarius and Scleroderma texense caused the lower toxicity to the nauplii. The brine shrimp bioassay was effective in evaluating the toxicity of Basidiomycota. Scleroderma texense has been reported to be toxic, but it was not for this crustacean nauplii, and probably not to humans either, as recent literature has reported.

An asymptotic-giant-branch star in the progenitor system of a type Ia supernova.

Stars that explode as supernovae come in two main classes. A type Ia supernova is recognized by the absence of hydrogen and the presence of elements such as silicon and sulphur in its spectrum; this class of supernova is thought to produce the majority of iron-peak elements in the Universe. They are also used as precise 'standard candles' to measure the distances to galaxies. While there is general agreement that a type Ia supernova is produced by an exploding white dwarf star, no progenitor system has ever been directly observed. Significant effort has gone into searching for circumstellar material to help discriminate between the possible kinds of progenitor systems, but no such material has hitherto been found associated with a type Ia supernova. Here we report the presence of strong hydrogen emission associated with the type Ia supernova SN2002ic, indicating the presence of large amounts of circumstellar material. We infer from this that the progenitor system contained a massive asymptotic-giant-branch star that lost several solar masses of hydrogen-rich gas before the supernova explosion.

Ab initio molecular dynamics study of the static, dynamic, and electronic properties of liquid mercury at room temperature.

We report a study on several static, dynamic, and electronic properties of liquid Hg at room temperature. We have performed ab initio molecular dynamics simulations using Kohn-Sham density functional theory combined with a nonlocal ultrasoft pseudopotential. The calculated static structure shows good agreement with the available experimental data. We present results for the single-particle dynamics, and recent experimental data are analyzed. The calculated dynamic structure factors S(q,omega) fairly agree with their experimental counterparts as measured by inelastic x-ray (and neutron) scattering experiments. The dispersion relation exhibits a positive dispersion, which however is not so marked as suggested by the experiment; moreover, its slope at the long-wavelength limit provides a good estimate of the experimental sound velocity. We have also analyzed the dynamical processes behind the S(q,omega) in terms of a model including a relaxation mechanism with both fast and slow characteristic time scales.

Structural and dynamical properties of liquid Mg. An orbital-free molecular dynamics study.

Several static and dynamic properties of liquid magnesium near melting have been evaluated by the orbital-free ab initio molecular dynamics method. The calculated static structure shows good agreement with recent experimental data, including an asymmetric second peak in the structure factor which has been linked to the existence of an important icosahedral short-range order in the liquid. As for the dynamic structure, we obtain collective density excitations with an associated dispersion relation which closely follows recent experimental results. Accurate estimates have also been obtained for several transport coefficients.

[Pterygium surgery: comparative study of conjunctival autograft with suture versus fibrin adhesive]. / Cirugía del pterigión: estudio comparativo entre autoinjerto conjuntival con sutura y con adhesivo tisular.

PURPOSE: To compare recurrence rate, complications, and biomicroscopical findings after conjunctival autograft pterygium surgery with the use of a fibrin glue (Tissucol Duo, Baxter AG, Vienna, Austria) or suture (7-0 silk). METHODS: Patients with nasal pterygium were included in two groups of conjunctival autograft surgery. In 9 of them the graft was sutured to the surrounding conjunctiva and in 8 of them the graft was fixed to the conjunctiva using fibrin glue. RESULTS: 17 patients (17 eyes) 41.2% women and 58.8% men were surgically treated. Mean patient age was 59.8 years. Five of the patients presented recurrence for simple excision and 12 presented primary pterygium. The extent of corneal invasion was 2 to 4 mm. In the suture group, 33.3% of the patients experienced pain after surgery compared to none in the fibrin glue group. In the suture group, 44.4% of the patients presented inflammation after surgery compared to none in the glue group. One patient from the glue group lost the graft and presented a recurrence one month later. CONCLUSIONS: The use of fibrin glue in pterygium surgery reduces patient symptoms, inflammation and discomfort. The rate of recurrence seems to be similar in both procedures.

Structural, dynamic, and electronic properties of liquid tin: An ab initio molecular dynamics study.

We report on a study of several structural, dynamic, and electronic properties of liquid Sn at a thermodynamic state close to the triple point (573 K) and another one at a higher temperature (1273 K). This study has been performed by ab initio molecular dynamics simulations using 205 atoms and around 20 ps of simulation time. The calculated static structures show a good agreement with the available experimental data. The dynamic structure factors fairly agree with their experimental counterparts obtained by inelastic x-ray scattering experiments, which display inelastic side peaks. The calculated dispersion relations exhibit a positive dispersion, although not so marked as suggested by the experiment; moreover, its slope at the long-wavelength limit compares favorably with the experimental sound velocity. Electron densities near selected triplets of atoms are similar to those appearing in the solid phases, but these features have an extremely short lifetime, so they should not be considered as solid remnants in the melt.

Structure of the liquid-vapor interfaces of Ga, In and the eutectic Ga-In alloy-an ab initio study.

We report the results of ab initio molecular dynamics simulations for the liquid-vapor interface of the liquid metals Ga, In and the eutectic binary alloy Ga-In (16.5% In) for which experimental data are available. The study was performed by using samples of 3000 particles in a slab geometry with periodic boundary conditions. In those systems, the total ionic density distributions along the normal to the interface display some layering and in the case of the Ga-In alloy there appears a highly enriched layer of the lower surface tension component located outermost at the interface. The results are compared with the available experimental data.

[Trans-scleral sutureless vitrectomy with a 25-G system for rhegmatogenous retinal detachment treatment]. / Cirugía del desprendimiento de retina regmatógeno mediante vitrectomía transescleral sin sutura con sistema 25-G.

PURPOSE: The evaluation of the trans-scleral sutureless vitrectomy (TSV) efficiency using a 25G system as an alternative in rhegmatogenous retinal detachment (RRD) treatment. METHODS: Patients treated for RRD with TSV have been reviewed taking into account their age, phakic or pseudophakic state, RRD localization and extension, surgical technique and post-operative resolution. RESULTS: Twenty two eyes of 22 patients have been treated for RRD with TSV. The average age was 54.3 years. 50% of the eyes were phakic. Eight of the detachments were "macula-off" at the time of diagnosis. SF6 was used in 5 cases and air in the remainder. Retinopexia of the breaks was done with trans-scleral cryocoagulation in 13 cases, with laser endophotocoagulation in 6 cases, and with both methods in 3 cases. The average follow-up time was 6.8 months, and the main complications were cataracts in 7 of 11 phakic eyes (63.6%) and a new retinal detachment in 4 eyes (18.2%). The intraocular pressures were similar to those before surgery and in 18 cases (81.8%) the visual acuity was better. CONCLUSION: TSV is effective in the treatment of RRD but with some limitations like the need for a learning period and a high incidence of cataracts.

Repeated administration of mazindol reduces spontaneous pain-related behaviors without modifying bone density and microarchitecture in a mouse model of complete Freund's adjuvant-induced knee arthritis.

BACKGROUND: The role of dopaminergic system in the development of rheumatoid arthritis-related pain, a major symptom in this disease, has not been explored. Therefore, the anti-nociceptive effect of mazindol, a dopamine uptake inhibitor, was evaluated in a model of complete Freund's adjuvant (CFA)-induced arthritis. Furthermore, as studies have shown that the dopaminergic system regulates bone metabolism, the effect of mazindol on bone mass and microarchitecture was determined. METHODS: Adult ICR male mice received intra-articular injections of either CFA or saline into the right knee joint every week. Spontaneous pain-like behaviors (flinching and guarding) and locomotor activity were assessed at day 26 post-first CFA, following which, a single intraperitoneally (i.p.) administered dose of mazindol was given (1, 3 and 10 mg/kg). Then, the antinociceptive effect of a repeated administration of 3 mg/kg mazindol (daily, i.p.; day 15-day 26) was evaluated. Additionally, at day 26, the participation of D1-like, D2-like or opioid receptors in the antinociceptive effect of mazindol was evaluated. The effect of mazindol on bone density and microarchitecture was evaluated by micro-computed tomography. RESULTS: Acute administration of mazindol decreased the spontaneous pain-like behaviors in a dose-dependent manner without reducing the knee edema. However, mazindol at 10 mg/kg significantly increased the locomotor activity; therefore, 3 mg/kg mazindol was used for further studies. Repeated administration of 3 mg/kg mazindol significantly decreased the pain-like behaviors without modifying locomotor activity. The antinociceptive effect of mazindol was blocked by administration of a D2-like receptor antagonist (haloperidol), but not by administration of D1-like receptor antagonist (SCH 23390) or an opioid receptor antagonist (naloxone). Repeated administration of mazindol did not significantly modify the density and microarchitecture of periarticular bone of the arthritic and nonarthritic knee joints. CONCLUSION: Results suggest that mazindol via D2-like receptors has an antinociceptive role in mice with CFA-induced knee arthritis without modifying the bone health negatively.

Can customized implants correct enophthalmos and delayed diplopia in post-traumatic orbital deformities? A volumetric analysis.

The purpose of this study was to determine whether orbital reconstruction with customized implants can correct post-traumatic orbital deformities such as late enophthalmos and delayed diplopia. The hypothesis proposed was that an overcorrection of the orbital volume is needed to resolve enophthalmos. A retrospective observational descriptive study was conducted. Patients with a major trauma who required customized orbital implants for the delayed treatment of unilateral orbital fractures that had initially been operated on using titanium mesh and/or osteosynthesis plates were included. The orbital volumes of the unaffected contralateral side, of the affected orbit after initial reconstruction with mesh, and of the affected orbit subsequently reconstructed with the customized implant were calculated. All of the patients included in this study had diplopia in the gaze position prior to the installation of the implant. In addition, they all had severe enophthalmos. After surgery, no patient with a customized implant showed diplopia. The enophthalmos was corrected in all but one case. On average, orbits reconstructed with customized implants had lower volumes compared to the unaffected contralateral side. In cases where the enophthalmos was resolved, the volume was reduced by an average of 8.55%. Further studies using a larger number of cases and with controlled volumetric corrections using CAD/CAM are needed.

[Development of a PCR for the detection and quantification of parasitism by Demodex folliculorum infestation in biopsies of skin neoplasms periocular area]. / Desarrollo de una PCR para la detección y cuantificación de la parasitación por Demodex folliculorum en biopsias de neoplasias cutáneas del área periocula.

OBJECTIVE: To standardize the relative quantification by mass of tissue parasitism by Demodex folliculorum infestation from neoplastic skin biopsies periocular using molecular amplification to study the possible relationship of the appearance of eyelid basal cell carcinoma with the presence and density of the mite in later works. METHODS: A quantitative PCR was developed real-time probes TaqMan. PCR was tested in a pilot 46 actual biopsy samples nodular basal cell carcinoma series. RESULTS: The sensitivity was placed with a detection limit of between 1 and 10 copies / µl. 50% (23/46) of the biopsies were positive for D. folliculorum. The specificity was 100% confirmed by sequencing. CONCLUSIONS: The technique shows good results for sensitivity and specificity that can make it useful as a tool for studies of cause and effect D. folliculorum and basal cell carcinoma.

[An orbital metastasis as the presentation of lung adenocarcinoma]. / Metástasis orbitaria como primera manifestación de adenocarcinoma pulmonar.

INTRODUCTION: Metastasis of primary tumours can involve the orbit via the blood stream. In 19% of cases this type of metastasis is the first oncologic symptom. CASE REPORT: A 42-year-old woman with a hard, well-defined nodule situated anteriorly in the right orbit and with mild associated inflammation. MR showed an oval image with homogeneous gadolinium uptake. On excision-biopsy a ductal cancer was found and determined on CAT scan to be of pulmonary origin. Chemotherapy was given and no recurrence occurred in the orbit. CONCLUSION: Ophthalmologic examination was the first step in the diagnosis of a metastasis of adenocarcinoma of the lung.

Role of the dorsomedial hypothalamus in mediating the response to benzodiazepines on trial 2 in the elevated plus-maze test of anxiety.

Trial 2 in the elevated plus-maze provides an animal model of specific phobia (fear of heights). On this trial, rats no longer respond to benzodiazepines. The present experiment examined the role of the dorsomedial hypothalamus in mediating insensitivity to chlordiazepoxide on trial 2. Rats received a 5 min exposure to the maze, undrugged. Forty-eight hours later, rats injected with control infusions into the dorsomedial hypothalamus showed the usual lack of response to chlordiazepoxide (5 mg/kg, i.p.). However, those receiving lidocaine injections (40 micrograms/microliter in a volume of 0.2 microliter) in the dorsomedial hypothalamus (producing functional inactivation), immediately before trial 2, responded with an anxiolytic response to chlordiazepoxide, characterised by an increased percentage of time on the open arms and by an increased number of entries into, and time spent on, the distal portions of the open arms. Since the lidocaine injections were without anxiolytic effects, our results suggest that this region of the hypothalamus regulates the functional state of benzodiazepine receptors in other brain regions.

Role of the basolateral nucleus of the amygdala in the formation of a phobia.

Specific phobia is an anxiety disorder that does not respond to benzodiazepines. The elevated plus-maze test of anxiety is sensitive to benzodiazepines on trial 1, but during the first 5-min trial the nature of the anxiety generated changes to a specific fear of heights, and, as a result, on trial 2 the rats no longer respond to benzodiazepines. However, rats that received reversible bilateral lesions of the basolateral amygdala (by lidocaine injection) immediately after trial 1 responded with an anxiolytic response to chlordiazepoxide when tested 48 h later on trial 2. Those that received vehicle injections after trial 1 showed the usual lack of response to chlordiazepoxide on trial 2. Thus, the basolateral amygdala plays a crucial role in the consolidation of information that leads to the formation of a specific phobia and subsequent insensitivity to benzodiazepines.

Selective amino acids changes in the medial and lateral preoptic area in the formalin test in rats.

A combination of microdialysis in freely moving rats and capillary zone electrophoresis coupled to laser induced fluorescence detection was used to measure extracellular concentrations of amino acid neurotransmitters in different hypothalamic areas during noxious stimulation. Arginine, glutamate and aspartate were monitored every 30 s before and after a s.c. injection of formalin (5%, 50 microl) or saline (0.9%) in the right hind paw. In the medial and lateral preoptic area, calcium and nerve impulse dependent increases of arginine, glutamate and aspartate were observed during the first 2 min after formalin injection. However, amino acid changes were not detected in the lateral hypothalamus or in the ventromedial nucleus when compared with pre-injection levels or with the levels from animals injected with saline in the hind paw. Flinching behavior was also scored during the first 10 min following the formalin or saline injection. Flinching frequency was maximum at minute 2 after formalin injection, whereas saline injection did not elicited any flinching behavior. These results show that nociceptive stimulation induces rapid and differential amino acids changes in discrete areas of the hypothalamus that can be associated with pain-related behavior.

Glutamate release in the nucleus accumbens is involved in behavioral depression during the PORSOLT swim test.

An abnormality in glutamate function has been implicated in the neural substrate of depressive disorders. To investigate this in rats, the Porsolt swim test was used to assess the role of glutamate in the nucleus accumbens. Glutamate injected into the nucleus accumbens dose-dependently decreased swimming time on the test day (day 2), whereas N-methyl-D-aspartate antagonists dizocilpine and 2-amino-5-phosphonovalerate increased swimming, like an antidepressant. Dizocilpine injected before the conditioning trial (day 1) did not modify the swimming times during the first day but abolished behavioral depression on day 2. Microdialysis coupled to capillary-zone electrophoresis was then used to determine in vivo changes in glutamate release in 1-min samples during the swim test. On day 1, glutamate increased significantly and reached a maximum of 222% after 3 min of swimming. On day 2, baseline glutamate levels were back to normal, but when the animal was placed in the water, glutamate increased to 419% during the first minute, and the animals swam significantly less. For comparison, tail pinch on consecutive days was used as a nonspecific, repeated stressor while accumbens glutamate levels were measured. Tail pinch on the first day increased glutamate similar to the effect obtained during the first day of swimming; however, a second day of tail pinch decreased glutamate levels, instead of the potentiated response observed during the second day of swimming. These results show that accumbens glutamate plays a role in causing the behavioral aspects of depressed behavior as modeled in the swim test. The accumbens may be a potential site of action for drugs that alter behavioral depression.