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1.
Heliyon ; 9(10): e20134, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37767480

ABSTRACT

A combined theoretical and experimental study was performed to elucidate the photocatalytic potential of tenorite, CuO (1 1 0) and to assess the evolution pathway of carbon dioxide (CO2) evolution pathway. The calculations were performed with density functional theory (DFT) at a DFT + U + J0 and spin polarized level. The CuO was experimentally synthesized and characterized with structural and optical methodologies. The band structure and density of states revealed the rise of band gaps at 1.24 and 1.03 eV with direct and indirect band gap nature, respectively. These values are in accordance with the experimental evidence at 1.28 and 0.96 eV; respectively, which were obtained by UV-Vis DRS. Such a behavior could be related to enhanced photocatalytic activity among copper oxide materials. Experimental evidence such as SEM images and work function measurements were also performed to evaluate the oxide. The redox potential suggests a catalytic character of tenorite (1 1 0) for the CO2 transformation through aldehydes (methanal) intermediate formation. Furthermore, a route through methylene glycol CH2(OH)2 was also explored with the theoretical methodology. The reaction path exhibits an immediate reduction of Image 1 into a •OH radical and an [OH]- anion, in the first step. This •OH radical attacks a double bond (C = O) of Image 2 to form bicarbonate ([Image 3]-) and subsequently, carbonic acid (Image 4). The carbonic acid reacts with other •OH radical to finally form orthocarbonic acid (Image 5).

2.
Biophys Chem ; 292: 106910, 2023 01.
Article in English | MEDLINE | ID: mdl-36327692

ABSTRACT

Porous Silicon (PSi) is an ideal material to build biosensors due to its large surface area and biocompatibility. However, it lacks of selectivity. By adhering bilayer lipids, active sites are added for vital biochemical processes. Such processes are promoted by different proteins, which aid to detect pollutants and drugs, among other. The present work is a systematic theoretical study at the density functional theory level on PSi models, functionalized with H and OH. Several concentrations of such functional groups were assessed at the pores to elucidate the reactivity via Fukui indexes of electrophilic and nucleophilic attack. The 1,2-dimyristoyl-sn-glycero-3-phosphocholine(DMPC) lipid was used as a probe system to interact with the PSi. The attraction was evaluated as electrostatic with a van der Waals contribution. The adsorption was highly selective to the degree of functionalization at the pore. The PSi facets (100) and (001) showed different mechanisms of interaction with the DMPC lipid. The theoretical absorption spectra addressed that the DMPC lipid could be identified with intensity variations coming from the degree of functionalization at the pore, which may be further rationalized experimentally. The present methodology may aid to tailor novel materials to capture and identify adverse agents present in the environment.


Subject(s)
Dimyristoylphosphatidylcholine , Lipid Bilayers , Humans , Dimyristoylphosphatidylcholine/chemistry , Lipid Bilayers/chemistry , Silicon , Porosity , Static Electricity
3.
Biomedicines ; 12(1)2023 Dec 27.
Article in English | MEDLINE | ID: mdl-38255175

ABSTRACT

There is a need for research addressing the functional characteristics of the motor end-plate in diabetes to identify mechanisms contributing to neuromuscular dysfunction. Here, we investigated the effect of diabetes on spontaneous acetylcholine release in the rat neuromuscular junction. We studied two randomized groups of male Wistar rats (n = 7 per group, 350 ± 50 g, 12-16 weeks of age): one with streptozotocin-induced experimental diabetes, and a healthy control group without diabetes. After 8 weeks of monitoring after diabetes induction, rats in both groups were anesthetized with pentobarbital. Then, the diaphragm muscle was dissected for electrophysiological recordings of miniature end-plate potentials (MEPPs) using a single electrode located at the region of the muscle end-plate. All experiments were conducted at environmental temperature (20-22 °C) in rat Ringer solution with constant bubbling carbogen (95% O2, 5% CO2). Compared to healthy controls, in the diaphragm neuromuscular end-plate derived from diabetic rats, the MEPPs were higher in amplitude and frequency, and the proportion of giant MEPPs was elevated (7.09% vs. 1.4% in controls). Our results showed that diabetes affected the acetylcholine MEPP pattern and increased the number of giant potentials compared to healthy controls.

4.
Pediatr Pulmonol ; 57(1): 285-292, 2022 01.
Article in English | MEDLINE | ID: mdl-34559461

ABSTRACT

Obstructive sleep apnea (OSA) affects between 2% and 4% in children and there is a search for new biomarkers that can be useful both in the diagnosis and in the evolution of the disease. The surfactant protein D (SP-D) is a collection that is part of the innate immune system exerting an anti-inflammatory and antimicrobial effect. Thus, the objective of this study was to evaluate the concentration of SP-D in the suspect OSA pediatric population. A total of 178 children were recruited in this prospective study. Blood samples, sleep parameters, feeding habits, anthropometric, sociodemographic, and family data were collected. Specific biochemical determinations were made, and the plasmatic concentrations of SP-D were measured by enzyme-linked immunosorbent assay. We found no statistical correlation between the SP-D concentration and the apnea-hypopnea index (AHI) from the data. Nevertheless, the changes in SP-D levels could be correlated to a large extent by the arousals that often go along with hypopneas (r = -0.258, p = 0.011 unadjusted; r = -0.258, p = 0.014 adjusted by age and body mass inded [BMI] Z-score). Intermittent hypoxia was correlated with C-reactive protein levels (r = 0.547, p < 0.001 unadjusted; r = 0.542, p < 0.001 adjusted by age and BMI Z-score). Although AHI and SP-D did not appear to correlate, a secondary analysis suggests that sleep fragmentation, which is produced by arousals, may do, and further research is needed to determine the mechanisms by which changes in SP-D occur in OSA.


Subject(s)
Pulmonary Surfactant-Associated Protein D , Sleep Apnea, Obstructive , Child , Humans , Hypoxia , Polysomnography , Prospective Studies , Sleep Apnea, Obstructive/diagnosis
5.
Data Brief ; 35: 106952, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33850983

ABSTRACT

This work presents data coming from electronic structure calculations at the Density Functional Theory level, performed in a series of organic photovoltaic materials. The data represents the Cartesian coordinates of such molecular systems at the lowest energy geometry and at the first excited state. Data evidencing the nature of the photo-isomerization in the OPV systems was also obtained. Additionally, the highest probabilities of the molecular electronic transitions giving rise to the absorption spectra observed in excited state were also computed. These data may aid to estimate photovoltaic parameters, and to tailor materials intended to be implemented in solar cell devices. They may also be used as input to design a training set for machine learning analysis and artificial intelligence.

6.
Nanoscale Adv ; 3(5): 1382-1391, 2021 Mar 09.
Article in English | MEDLINE | ID: mdl-36132868

ABSTRACT

Herein, we report a systematic experimental and theoretical study about a wide-ranged band gap tuning of protonated titanate nanotubes H2Ti3O7 (Ti-NT) by an easy ion-exchange method using a low concentration (1 wt%) of transition metal cations. To characterize and describe the effect of M doping (M = Cu2+, Ni2+, Co2+, and Fe3+) on the electronic, optical and structural properties, semiconductors were analyzed by a combination of experimental methods and density functional theory (DFT) calculations. The nanotube band gap can be modified from 1.5 to 3.3 eV, which opens the possibility to use them in several optoelectronic applications such as photocatalysts under solar light irradiation.

7.
J Colloid Interface Sci ; 585: 649-659, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33153713

ABSTRACT

Increasing the electrochemical performance of electrode materials in sodium ion batteries (NIBs) remains a major challenge. Here, a combined experimental and theoretical investigation on the modification induced by Sb2S3 embedded in a heteroatom-doped 3D carbon matrix (CM) for efficient anodes in NIBs is presented. The structural and chemical characterization demonstrates the successful doping of 3D CM with S and Sb atoms. When evaluated as anode materials for NIBs, the heteroatom-doped nanocomposites delivered a better cycling stability and superior rate capability than those of undoped Sb2S3/CM anodes. First principle calculations were used at the Density Functional Theory level to systematically study the Sb2S3/CM and Sb2S3/heteroatom doped-CM composites, as NIBs anodes. Doping the carbon substrate by heteroatoms improved the adsorption of Sb2S3 on the matrix and allowed for ionic/covalent attraction with the Sb2S3 nanoparticle, respectively. Such results could be used to model the stabilty of the composite architectures observed in the experiment, for superior cycling stability.

8.
J Musculoskelet Neuronal Interact ; 19(3): 354-361, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31475943

ABSTRACT

OBJECTIVE: This study aimed to examine the effects of moderate (MIT) and high-intensity training (HIT) chronic exercise on plasma tumor necrosis factor alpha (TNF-α) level and its impact on Langerhans islet morphology in healthy rats. METHODS: Two-month old normal male Wistar rats were divided into three groups: control (C, n=6), MIT (n=6), and HIT (n=4). The training protocol consisted in 24 sessions of running on a treadmill at 60-80% maximal oxygen consumption (VO2max) for MIT, and >80% VO2max for HIT. TNF-α and insulin were measured with ELISA tests. Duodenal pancreas was dissected to analyze the Langerhans islets by immunohistochemistry, a correlation analysis was performed with the nuclei/total islet area. Results: HIT and MIT rats showed lower TNF-α plasma levels than controls. Plasma insulin level decreased significantly in HIT compared with C and MIT. In addition, the islet area and nuclei density per islet were higher in the exercise groups compared with C. However, none of the groups showed PD1 immunoreactivity. CONCLUSIONS: Under healthy conditions, the chronic exercise reduced plasmatic TNF-α level, and in the same sense, increased the size of the Langerhans islets, depending to the exercise intensity.


Subject(s)
Islets of Langerhans , Physical Conditioning, Animal/physiology , Tumor Necrosis Factor-alpha/blood , Animals , Male , Rats , Rats, Wistar
9.
Medicina (Kaunas) ; 55(6)2019 Jun 19.
Article in English | MEDLINE | ID: mdl-31248228

ABSTRACT

Background and objectives: Adipose tissue and skeletal muscle secrete adiponectin, a hormone abundantly secreted by adipocytes, that through the adiponectin receptor, regulate glucose and lipid metabolism. Adiponectin appears to protect skeletal muscles from inflammatory damage induced by oxidative stress. It has been suggested that decreased adiponectin levels could be associated with pathologic conditions, including obesity and diabetes. Furthermore, some studies suggest that exercise could have a beneficial effect by increasing adiponectin levels, but this observation remains controversial. It is also unknown if physical exercise modifies adiponectin expression in skeletal muscles. The aim of this study was to investigate the effect of chronic exercise on serum adiponectin and adiponectin expression in slow-twitch (soleus) and fast-twitch (plantaris) muscles in healthy rats. Materials and methods: Two-month-old male Wistar rats were randomly divided into three groups with n = 6 in each group: control (C), moderate-intensity training (MIT), and high-intensity training (HIT). The rats were conditioned to run on a treadmill for the 8-week period. Forty-eight hours after the last session, blood samples were collected for adiponectin measurements and total RNA was isolated from plantaris and soleus muscles to measure by RT-qPCR adiponectin receptor 1 and adiponectin mRNA expression level. Results: MIT and HIT groups had reduced adiponectin protein levels in serum and the plantaris muscle, but not changes in adiponectin protein were observed in the soleus muscle. No significant differences in Adiponectin receptor 1 (AdipoR1) gene expression were observed following intense or moderate exercise in either muscle group studied. Conclusions: Our study shows that decreasing levels of circulating adiponectin is a result of physical exercise and should not be generalized as a predictive marker of disease.


Subject(s)
Adiponectin/analysis , Muscle, Skeletal/pathology , Physical Conditioning, Animal/physiology , Adiponectin/blood , Analysis of Variance , Animals , Disease Models, Animal , Male , Muscle, Skeletal/physiology , RNA/analysis , RNA/blood , Rats , Rats, Wistar/blood
10.
Data Brief ; 24: 103874, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31008160

ABSTRACT

This article contains data on nanoporous carbon materials coming from lignocellulosic components. Such data is directly related to the research paper "Insights into the design of carbon electrodes coming from lignocellulosic components pyrolysis with potential application in energy storage devices: A combined in silico and experimental study" [1]. In this work, the geometrical parameters of nanoporous carbon systems were found with Molecular Dynamics (MD) simulations at the ReaxFF level. The tridimensional structures of such carbon systems are given in Cartesian coordinates. They were computed at different heating rates, simulating the conditions observed in pyrolysis processes of Agave angustifolia leaves, which were carried out in a solar furnace. Nanoporous carbon systems are characterized with radial distribution functions (RDF) and ring distribution profiles.

11.
J Musculoskelet Neuronal Interact ; 18(2): 255-261, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29855448

ABSTRACT

In the present study, we studied the effect of streptozotocin-induced Type 1 diabetes on contractile properties of soleus muscle in female and young male rats. We hypothesized that the gender affects the contractile function in diabetic rats. Thirty-two Sprague-Dawley rats, male and female, three months old were divided into four groups: Female Non-Diabetic (FND), Female Diabetic (FD), Male Non-Diabetic (MND) and Male Diabetic (MD). Diabetes was induced by a single dose of 60 mg/kg body weight of streptozotocin in citrate buffer pH 4.5 by intraperitoneal route. At 4 weeks after of the dose animals were considered to be diabetic if they had glucose levels ≥20 mmol/L. Soleus muscle mass and twitch force were higher in MND than in FND; in male rats, the diabetes decreased the muscle mass in 34% and the twitch force decayed in 33%; while in diabetic females the muscle mass and twitch force decayed 15% and 10% respectively. Our results showed that the diabetes has gender-dependent effects on the muscle mass and maximal contractile force.


Subject(s)
Diabetes Mellitus, Experimental/physiopathology , Muscle Contraction/physiology , Muscle, Skeletal/physiopathology , Animals , Body Weight/physiology , Female , Male , Rats , Rats, Sprague-Dawley , Sex Factors
12.
Muscle Nerve ; 53(3): 446-51, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26148339

ABSTRACT

INTRODUCTION: Brain-derived neurotrophic factor (BDNF) protein expression is sensitive to cellular activity. In the sedentary state, BDNF expression is affected by the muscle phenotype. METHODS: Eighteen Wistar rats were divided into the following 3 groups: sedentary (S); moderate-intensity training (MIT); and high-intensity training (HIT). The training protocol lasted 8 weeks. Forty-eight hours after training, total RNA and protein levels in the soleus and plantaris muscles were obtained. RESULTS: In the plantaris, the BDNF protein level was lower in the HIT than in the S group (P < 0.05). A similar effect was found in the soleus (without significant difference). In the soleus, higher Bdnf mRNA levels were found in the HIT group (P < 0.001 vs. S and MIT groups). In the plantaris muscle, similar Bdnf mRNA levels were found in all groups. CONCLUSIONS: These results indicate that high-intensity chronic exercise reduces BDNF protein level in fast muscles and increases Bdnf mRNA levels in slow muscles.


Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Gene Expression Regulation/physiology , Muscle Contraction/physiology , Muscle, Skeletal/physiology , Physical Conditioning, Animal , Physical Endurance/physiology , Analysis of Variance , Animals , Brain-Derived Neurotrophic Factor/genetics , Male , RNA, Messenger/metabolism , Rats , Rats, Wistar
13.
Acta Neurochir (Wien) ; 157(8): 1339-43; discussion 1343, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26085111

ABSTRACT

Sparganosis is a severe parasitic infection caused by the larvae of Spirometra mansoni, also called "sparganum." In human hosts, the Spirometra mansoni larva commonly targets the subcutaneous tissue or muscle. Sometimes it can also migrate into the brain, resulting in cerebral sparganosis, mainly characterized by focal neurological symptoms such as seizures and radiological "wandering lesions" on magnetic resonance images (MRIs). Clinical cases of cerebral sparganosis have been reported worldwide, mainly in Asian countries, but also in North America, South America and Australia. Only two cases have been previously reported in Europe. A 29-year-old male from Bolivia, who lived in Spain, presented to our service for seizures and a multicystic brain lesion, initially suspected to be a dysembryoplastic neuroepithelial tumor (DNET). He underwent gross total resection of the mixed solid/cystic lesion. Pathology revealed gliosis, multiple interconnected cystic cavities with fibrous walls, inflammatory cell infiltration and no necrotizing granulomatous reaction. Inside the cavities, a parasitic form was identified as the larva of the cestode Spirometra mansoni. At 1-year follow-up, the patient had no deficits and was seizure free. Clinicians should be alerted to the possible existence of this rare entity in Europe, especially in patients from endemic areas with a possible infection history as well as "wandering lesions" on the MRI.


Subject(s)
Brain Diseases/diagnosis , Brain Diseases/parasitology , Magnetic Resonance Imaging , Sparganosis/diagnosis , Sparganosis/pathology , Adult , Animals , Brain/parasitology , Brain/pathology , Brain/surgery , Brain Diseases/surgery , Craniotomy , Europe , Humans , Male , Neurosurgical Procedures , Seizures/etiology , Seizures/parasitology , Spain , Sparganosis/surgery , Spirometra/isolation & purification , Treatment Outcome
14.
Bol Asoc Med P R ; 107(3): 66-9, 2015.
Article in English | MEDLINE | ID: mdl-26742199

ABSTRACT

The objective was to describe the metabolic outcomes 12 months after bariatric surgery (Roux-N-Y) in morbidly obese Hispanic patients, and evaluate the correlation between weight loss and the observed changes. Medical records from a hundred-and-two Hispanic obese patients who underwent bariatric surgery were identified at the University of Puerto Rico (UPR) Hospital. The following variables were obtained before and 12 months after surgery: Body Mass Index (BMI), body weight, total cholesterol (TC), triglycerides, high density lipoprotein (HDL), low density lipoprotein (LDL), and fasting blood sugar (FBS). Ninety-seven percent of patients underwent Roux-N-Y surgery; 79.4% were females and 44% were diabetics. We observed statistically significant reductions (p < 0.05) 12 months after surgery in: BMI -14.3 (± 6.2) kg/m2, weight -86.1 (± 34.4) Ibs, TC -17.9 (± 32.4) mg/dL, triglycerides -28.7(± 40.6) mg/dL, LDL-15.4 (± 30.6) mg/dL, and FBS -11.3 (± 23.5) mg/dL. HDL, instead increased +5.22 (± 12.9) mg/dL (p < 0.0006). Gastric bypass surgery of the Roux-N-Y significantly improves the lipid profile and FBS levels in obese Hispanic patients. The poor correlation factor between weight loss and these variables suggests that other mechanisms, independent from weight loss, are responsible for these changes.


Subject(s)
Blood Glucose/analysis , Gastric Bypass , Hispanic or Latino , Lipids/blood , Adult , Body Mass Index , Body Weight , Female , Humans , Insulin Resistance , Male , Metabolic Syndrome/metabolism , Metabolic Syndrome/surgery , Middle Aged , Obesity/metabolism , Obesity/surgery , Postoperative Period , Puerto Rico/ethnology , Retrospective Studies , United States , Weight Loss
15.
Biomed Res Int ; 2014: 984785, 2014.
Article in English | MEDLINE | ID: mdl-25147829

ABSTRACT

The pathologic cardiac remodeling has been widely documented; however, the physiological cardiac remodeling induced by pregnancy and its reversion in postpartum are poorly understood. In the present study we investigated the changes in collagen I (Col I) and collagen III (Col III) mRNA and protein levels in left ventricle from rat heart during pregnancy and postpartum. Col I and Col III mRNA expression in left ventricle samples during pregnancy and postpartum were analyzed by using quantitative PCR. Data obtained from gene expression show that Col I and Col III in left ventricle are upregulated during pregnancy with reversion in postpartum. In contrast to gene expression, the protein expression evaluated by western blot showed that Col I is downregulated and Col III is upregulated in left ventricle during pregnancy. In conclusion, the pregnancy differentially regulates collagens types I and III in heart; this finding could be an important molecular mechanism that regulates the ventricular stiffness in response to blood volume overload present during pregnancy which is reversed in postpartum.


Subject(s)
Collagen Type III/genetics , Collagen Type III/metabolism , Collagen Type I/genetics , Collagen Type I/metabolism , Heart Ventricles/metabolism , Animals , Down-Regulation/genetics , Female , Gene Expression/genetics , Postpartum Period/genetics , Pregnancy , RNA, Messenger/genetics , Rats , Rats, Sprague-Dawley , Up-Regulation/genetics
16.
J Neurointerv Surg ; 6(3): e20, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24610142

ABSTRACT

Cerebral arteriovenous malformations (AVMs) are uncommon. Treatment options include embolization, radiosurgery and surgery, separately or combined, the final goal being complete occlusion of the malformation. We describe the case of a symptomatic small subependymal AVM with a single deep drainage vein previously treated unsuccessfully by radiosurgery and transarterial embolization. The AVM was successfully embolized transvenously using Onyx, achieving complete occlusion in a single treatment session.


Subject(s)
Cerebral Veins/pathology , Embolization, Therapeutic/methods , Ependyma/blood supply , Intracranial Arteriovenous Malformations/therapy , Lateral Ventricles/blood supply , Cerebral Veins/diagnostic imaging , Dimethyl Sulfoxide/therapeutic use , Embolization, Therapeutic/instrumentation , Female , Humans , Intracranial Arteriovenous Malformations/diagnostic imaging , Intracranial Arteriovenous Malformations/pathology , Lateral Ventricles/diagnostic imaging , Middle Aged , Polyvinyls/therapeutic use , Radiography , Treatment Outcome
17.
BMJ Case Rep ; 20132013 Mar 28.
Article in English | MEDLINE | ID: mdl-23542648

ABSTRACT

Cerebral arteriovenous malformations (AVMs) are uncommon. Treatment options include embolization, radiosurgery and surgery, separately or combined, the final goal being complete occlusion of the malformation. We describe the case of a symptomatic small subependymal AVM with a single deep drainage vein previously treated unsuccessfully by radiosurgery and transarterial embolization. The AVM was successfully embolized transvenously using Onyx, achieving complete occlusion in a single treatment session.


Subject(s)
Dimethyl Sulfoxide/administration & dosage , Embolization, Therapeutic/methods , Intracranial Arteriovenous Malformations/therapy , Polyvinyls/administration & dosage , Ependyma , Female , Humans , Intracranial Arteriovenous Malformations/pathology , Middle Aged , Veins
18.
Exp Parasitol ; 128(4): 301-8, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21334326

ABSTRACT

Parasitism in skeletal muscles and myositis are commonly observed during experimental Trypanosoma cruzi infection. The effect of T. cruzi infection on contractile properties of skeletal muscles in consecutive periods of the acute infection in BALB/c mice was studied. Albarrada strain (clone 4) which was isolated in Mexico and has demonstrated a high level of blood parasitemia and parasitism in skeletal muscles was used. Isolated strips of rectus abdominis muscle were subjected to direct electrical field in vitro. Alternatively, plantaris muscles were stimulated in situ through the sciatic nerve. The peak amplitudes of a single twitch and tetanus contractions were considered to estimate the mechanical properties of muscles. Histopathological analysis was performed to correlate functional changes with the evolution of tissue parasitism and tissue injury. Contractile properties of muscles were significantly attenuated during acute T. cruzi infection. The percentage of damaged muscles rather than the character of tissue pathology affected their contractile properties significantly.


Subject(s)
Chagas Disease/physiopathology , Muscle Contraction/physiology , Muscle, Skeletal/pathology , Acute Disease , Animals , Chagas Disease/parasitology , Chagas Disease/pathology , Electric Stimulation/methods , In Vitro Techniques , Insect Vectors/parasitology , Male , Mice , Mice, Inbred BALB C , Muscle, Skeletal/parasitology , Muscle, Skeletal/physiopathology , Parasitemia/parasitology , Parasitemia/pathology , Parasitemia/physiopathology , Random Allocation , Rectus Abdominis/parasitology , Rectus Abdominis/pathology , Rectus Abdominis/physiopathology , Triatominae/parasitology
19.
Chemistry ; 17(1): 368-77, 2011 Jan 03.
Article in English | MEDLINE | ID: mdl-21207633

ABSTRACT

The effect of the ligand L on the aurophilic Au(I) ⋅⋅⋅Au(I) closed-shell interaction in perpendicular [{ClAuL}(2) ] model systems is investigated. An analogous study of the effect of the halide X (here Cl) exists, and showed a correlation with the softness of the ligand X. In this work, we study the correlation with L=N-heterocyclic carbenes (NHC), cyclic diphosphinocarbenes (PHC), NF(3) , CO, methyl isocyanide CNMe, PF(3) , SH(2) , NH(3) , H(2) O, pyridine, triazene, the carbodiphosphorene model C(PH(3) )(2) , C(3) H(2) , and the related model systems CN(2) or CP(2) . The NHCs yield stronger interactions than PH(3) . The spatial orientation of certain ligands in a "paddle" configuration plays an important role on the strength of the interaction. All are examples on aurophilicity.

20.
Gen Physiol Biophys ; 29(2): 129-33, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20577024

ABSTRACT

We use laser diffraction in the analysis of the transversal deformation that the papillary muscle of the female and male Wistar rat may undergo when is subjected to different tension (tension range, 0-30 mN) in the longitudinal plane. Papillary muscles from the right ventricle were illuminated at normal incidence with a He-Ne laser lasing at 594 nm at room temperature. The far-field diffraction pattern projected to a screen was recorded with a digital camera for its analysis. The analysis of the stress-strain curves from the two experimental groups shows that the papillary muscles from male rats exhibit a higher stiffness in the transversal axis compared to the female rats.


Subject(s)
Papillary Muscles/physiology , Animals , Biomechanical Phenomena , Excitation Contraction Coupling/physiology , Female , In Vitro Techniques , Lasers , Male , Myocardial Contraction/physiology , Rats , Rats, Wistar , Stress, Mechanical
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