This study aimed to characterize the physical-chemical and biological properties of pectin(PC)/chia seed mucilage(CM)membranes.PC/CM[100/0(control),80/20%,60/40%,and 40/60%w/w]membranes were prepared using the casting...This study aimed to characterize the physical-chemical and biological properties of pectin(PC)/chia seed mucilage(CM)membranes.PC/CM[100/0(control),80/20%,60/40%,and 40/60%w/w]membranes were prepared using the casting method.The membranes(PC/CM)were thin,yellow,lightly opaque(≈10%)and capable of blocking light UVB(between 66 at 52%).SEM analysis showed the presence of aggregates in the shape of a sphere(≈13μm)and ovoid(≈25μm).The proportion of 80/20 showed an increase in tensile strength(29%)and elastic modulus(19%)when compared to the control.FTIR analysis exhibited intermolecular interactions between PCPC,PC-CM,and CM-CM in the membranes.The thermal analysis(600°C)showed a slight improvement in the percentage of residual mass-loss of 3.31%(80/20)that control.The 40/60 membrane showed the lowest percentage of hemolysis(2.94%)but limited human albumin adsorption capacity.These results suggested that the blend PC/CM may be considered as a biomaterial for medical applications.展开更多
Ischemic stroke is the most common type of cerebrovascular disease and is caused by an interruption of blood flow in the brain.In this disease,two different damage areas are identifying:the lesion core,in which cells ...Ischemic stroke is the most common type of cerebrovascular disease and is caused by an interruption of blood flow in the brain.In this disease,two different damage areas are identifying:the lesion core,in which cells quickly die;and the penumbra(surrounding the lesion core),in which cells are functionally weakened but may recover and restore their functions.The currently approved treatments for ischemic stroke are the recombinant tissue plasminogen activator and endovascular thrombectomy,but they have a short therapeutic window(4.5 and 6 hours after stroke onset,respectively)and a low percentage of stroke patients actually receive these treatments.Memantine is an approved drug for the treatment of Alzheimer's disease.Memantine is a noncompetitive,low affinity and use-dependent antagonist of N-methyl-D-aspartate glutamate receptor.Memantine has several advantages over developing a new drug to treat focal ischemic stroke,but the most important is that it has sufficient safe probes in preclinical models and humans,and if the preclinical studies provide more evidence about pharmacological actions in tissue protection and repair,this could help to increase the number of clinical trials.The present review summarizes the physiopathology of isquemic stroke and the pharmacological actions in neuroprotection and neuroplasticity of memantine in the post stroke stage of preclinical stroke models,to illustrate their potential to improve functional recovery in human patients.展开更多
Background:Dry eye is a multifactor disease of the tear film and ocular surface that substantially affects quality of life.Case presentation:Dobesilate administered as eye drops was well tolerated and effective in tre...Background:Dry eye is a multifactor disease of the tear film and ocular surface that substantially affects quality of life.Case presentation:Dobesilate administered as eye drops was well tolerated and effective in treating both the objective signs and subjective symptoms of dry eye disease in this 2-week study.Conclusion:To the best of our knowledge,this is the first clinical report of using dobesilate in eye drops.Dobesilate may provide a novel approach to treating drying diseases of the eye.展开更多
Vitreous hemorrhages are important clinical manifestations of proliferative diabetic retinopathy. Non-cleared vitreous hemorrhages could lead to hemosiderosis bulbi and glaucoma. Here, we describe the case of a type 2...Vitreous hemorrhages are important clinical manifestations of proliferative diabetic retinopathy. Non-cleared vitreous hemorrhages could lead to hemosiderosis bulbi and glaucoma. Here, we describe the case of a type 2 diabetic patient presenting anterior segment and vitreous hemorrhages that resolved three days after treatment with a single intravitreal injection of dobesilate.展开更多
The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of ...The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of 100 and 300 mg·L-1, respectively. Both metal ions had insignificant inhibitory effect over the metabolism of the biomass, specifically, on substrate consumption and production of volatile fatty acids (VFAs). The microstructural characterization of the biofilm by Scanning Electron Microscopy showed no effect on the morphology of the microorganisms after the metals treatment. Copper and iron removal was also measured in the reactor, achieving a breakthrough time of 3 days, during which removal efficiencies were higher than 90%. It was also observed that the biomass had a greater affinity for copper. The results indicate that acidogenic biomass can be used effectively as a sorbent agent. The pollution of river-streams with heavy metals—mainly copper and iron—was one of the most compelling motivations for conducting this investigation. The San Pedro River Basin, a trans-boundary river that originates near the mining town of Cananea, Sonora, México, and flows to Arizona, USA, exemplifies this environmental issue.展开更多
Bacterial infections are highly prevalent and a frequent cause of hospitalization and short-term mortality in patients with cirrhosis. Due to their negative impact on survival, antibiotic prophylaxis for bacterial inf...Bacterial infections are highly prevalent and a frequent cause of hospitalization and short-term mortality in patients with cirrhosis. Due to their negative impact on survival, antibiotic prophylaxis for bacterial infections in high-risk subgroups of patients with cirrhosis has been the standard of care for decades. Patients with prophylaxis indications include those at risk for a first episode of spontaneous bacterial peritonitis(SBP) due to a low ascitic fluid protein count and impaired liver and kidney function, patients with a prior episode of SBP and those with an episode of gastrointestinal bleeding. Only prophylaxis due to gastrointestinal bleeding has a known and short-time duration. All other indications imply longlasting exposure to antibiotics-once the threshold requirement for initiating prophylaxis is met-without standardized criteria for re-assessing antibiotic interruption. Despite the fact that the benefit of antibiotic prophylaxis in reducing bacterial infections episodes and mortality has been thoroughly reported, the extended use of antibiotics in patients with cirrhosis has also had negative consequences, including the emergence of multi-drug resistant bacteria.Currently, it is not clear whether restricting the use of broad and fixed antibiotic regimens, tailoring the choice of antibiotics to local bacterial epidemiology or selecting non-antibiotic strategies will be the preferred antibiotic prophylaxis strategy for patients with cirrhosis in the future.展开更多
The extraction of bioactive compounds has become one of the most interesting areas of modern chemistry.For therapeutic reasons,it´s important to obtain antimicrobial agents from natural origin.The objective of th...The extraction of bioactive compounds has become one of the most interesting areas of modern chemistry.For therapeutic reasons,it´s important to obtain antimicrobial agents from natural origin.The objective of the present study was to determine the inhibitory effect of ethanolic extract of basil(Ocimum basilicum L.var.Red Rubin)subjected to different concentrations of potassium(K^(+))on the activity of three bacterial strains that are pathogens in humans.Susceptibility was evaluated by inhibition surface and these results were compared to two antibiotics:Gentamicin(GE)and Ciprofloxacin(CPF)for their efficacy against each bacterial strain.Analyzed variables presented significant difference(p≤0.05).According to the results,basil extract evaluated showed positive antibacterial activity against the three strains of Pseudomonas aeruginosa,Listeria monocytogenes and Staphylococcus aureus on Mueller Hinton agar.It was observed highest inhibition areas of different diameters(15.3 mm,21.3 mm and 21.6 mm respectively)when the extract used was obtained from the plants with the highest concentration of potassium(13 mmol L-1).These values were even superior to the highest values showed on the treatments with the antibiotic gentamicin.展开更多
Animal protein foods are undoubtedly among the most concentrated source of essential amino acids (AA) for the human diet. However, their high prices and diseases associated to their excessive consumption have fomented...Animal protein foods are undoubtedly among the most concentrated source of essential amino acids (AA) for the human diet. However, their high prices and diseases associated to their excessive consumption have fomented the consumption of other alternative sources of animal proteins such as those from marine or aquatic species. Sonora is a well recognized producer of animal foods in Mexico, both terrestrial and aquatic. In this study, the protein quality evaluation of these animal food sources, highly produced and consumed in Sonora, is proposed, using in-vitro methodologies. Four different species, from each aquatic and terrestrial origin, were selected. Samples of lean muscle were used in all cases. Various in-vitro methodologies for protein quality evaluation were selected, alternatives to the animal bioassays: % digestibility, Total amino acid analyses (HPLC), PDCAAS, computerized PER calculations (C-PER and DC-PER) and total collagen contents. % in-vitro digestibility presented significant differences among samples from terrestrial species, but muscle from aquatic species did not showed significant differences. All sources of proteins, both aquatic and terrestrial proved to be rich sources of essential amino acids. PDCAAS was unable to establish significant differences in protein quality among sources of protein from different origin. Both methods C-PER and DC-PER were more exact in their results and were able to detect significant differences among samples of different origin. An important finding was the great difference in the total collagen content between aquatic and terrestrial sources of proteins, where terrestrial muscle proteins had almost 10-time more collagen than aquatic protein sources. However, these collagen contents did not seem to have a significant influence in the protein quality of these animal proteins. These muscle proteins, from both aquatic and terrestrial species, confirmed to have a high protein quality and some of the in-vitro methodologies used in this study represent a valuable alternative to the animal bioassays.展开更多
Cereal crop improvement programmes involve the analysis of a great number of lines every year;the availability of a simple, rapid method that would allow the identification of a trait in the early stages of plant deve...Cereal crop improvement programmes involve the analysis of a great number of lines every year;the availability of a simple, rapid method that would allow the identification of a trait in the early stages of plant development would facilitate the selection process. This work reports two experiments involving the germination of seeds in Petri dishes, performed to study the effect of water deficit on the growth of barley coleoptiles. In one experiment water stress was induced by allowing evaporation from the Petri dishes;in the other water stress was achieved by adding polyethylene glycol 6000. The growth of the control coleoptiles was greater than that of the treatment coleoptiles in all cases, but with differences between the different genotypes. A significant correlation (P < 0.01) was found between the relative growth of the coleoptiles and turgor maintenance in the seedlings. Significant correlations were also seen between the relative growth of the coleop-tiles and the osmotic adjustment of the flag leaf (P < 0.05) and the grain weight (P < 0.01) in adult plants. The genotypes that showed the greatest relative growth also showed the greatest capacity for osmotic adjustment in the flag leaf and produced the greatest yields in experiments with adult plants. The results indicate that the growth of coleoptiles subjected to water deficit could be used as a selection criterion in breeding programmes designed to improve the tolerance of barley to drought.展开更多
Objective: It is in order to estimate the prevalence and incidence of HIV, the frequency of sexual risk behaviors, and perceptions of available resources to prevent and treat HIV among crack users in the San Salvador ...Objective: It is in order to estimate the prevalence and incidence of HIV, the frequency of sexual risk behaviors, and perceptions of available resources to prevent and treat HIV among crack users in the San Salvador Metropolitan Area. Methods: We conducted a survey of 420 crack users by using respondent-driven sampling to measure demographic characteristics, the quantity and frequency of drug use, history of STIs, including HIV, and experiences with organizations which provide prevention and treatment of HIV. Each participant offered a free and voluntary HIV test and was asked permission to share the results of the test with the study. Bernoullian modeling was used to estimate the prevalence and incidence of HIV among heterosexual males in this population. Results: The estimated prevalence was 7% (95% CI: 2.3% -9.8%) among participants who agreed to take the test and share the results, and 4.9% (95% CI: 2.8% -7.8%) assuming that those who did not take the test or share results were seronegative. Participants reported a high frequency of sexual risk behaviors. In addition, participants were reported to have little knowledge of organizations to prevent or treat HIV/AIDS;58% had never taken an HIV test prior to survey administration. Conclusions: Crack users in San Salvador are at high risk for HIV acquisition. HIV prevention interventions are urgently needed, especially interventions increasing access to HIV testing and prevention.展开更多
Urolithiasis (UL) is an endemic disease in Southeastern, Mexico. In order to evaluate the association of I550V polymorphism in the hNaDC-1 gene with risk for hypocitraturia and/or for UL;139 adults with UL and 132 adu...Urolithiasis (UL) is an endemic disease in Southeastern, Mexico. In order to evaluate the association of I550V polymorphism in the hNaDC-1 gene with risk for hypocitraturia and/or for UL;139 adults with UL and 132 adults without UL, were included under a case-control association study. Citrate levels in 24-h urine were quantified (citraturia). The polymorphism I550V-hNaDC-1 was determined by PCR-RFLP. Statistical analysis was performed using the STATA10.2 software. Comparison of genotype and allele frequencies between subjects with and without UL showed significant differences for genotype bb (OR = 2.34, CI: 1.19-4.59, p = 0.01) and for allele b (OR = 1.62, CI: 1.15-2.28, p = 0.005), suggesting an association with the risk for UL. Comparison of genotype and allele frequencies between subjects with hypocitraturia and subjects with normocitraturia, did not show any significant difference (p > 0.05), suggesting that this polymorphism is not associated with the risk of hypocitraturia. Interestingly, the risk for UL was increased due to an additive effect of hypocitraturia with the genotype bb (OR = 6.6, CI: 2.38-18.28, p = 0.0002) or with the allele b (OR: 4.2, CI = 2.52-6.97,展开更多
Despite the breadth of knowledge about malaria, its transmission, preventive measures and available treatments and its difficulty in controlling the vector and the rapid spread of resistance to current drugs, there is...Despite the breadth of knowledge about malaria, its transmission, preventive measures and available treatments and its difficulty in controlling the vector and the rapid spread of resistance to current drugs, there is a stimulus to develop new research looking for active molecules. The phytochemical studies of the active extract confirmed the presence of alkaloids, flavonoids, coumarins, tannins, reducing compounds, anthocyanins, terpenes, triterpenes and steroids. In the present work, it was possible to isolate a mixture of isoquinolinic alkaloids from the tender leaves of Nectandra membranacea (Laureaceae) with antimalarial activity. The mixture composed of (-) - gliazovine and (+) - aplogliazovine showed an IC50 value of 32.18 μg/mL against the P. berghei NK65 strain. It is important to continue with these studies and their chemical components isolated from N. membranacea that could be used as an alternative the treatment of malaria.展开更多
Candidiasis is the most common opportunistic fungal infection in HIV patients, and its presence is ascribed mainly to the persistence of the original infecting strain. The latter might acquire genetic variations durin...Candidiasis is the most common opportunistic fungal infection in HIV patients, and its presence is ascribed mainly to the persistence of the original infecting strain. The latter might acquire genetic variations during interaction with the host, reflecting the adaptation of the strain. Here, we report the case of a 32-year-old man complaining of asthenia, irregular hyperpyrexia, and dry cough, who was admitted to the emergency unit. Laboratory examination showed positivity for HIV. Dark violet macular lesions and ulcerated lesions with verrucous erosion were observed at the tip of the nose, whereas an ulcer without exudates was noted in the pubic region. Candida albicans was recovered from the skin by scraping these lesions. Cultures from the bronchoalveolar lavage (BAL) were negative for bacteria and opportunistic fungi but were positive for Candida albicans. The isolates from the skin and BAL were typed by PCR-RFLP and Candida albicans was identified. Analysis by microsatellite length polymorphisms, established that the pubic isolate was a genetic variant of the isolate from the nose and mouth. This suggested a microevolutionary event. Despite clinical support, the patient died of multiple organ failure.展开更多
The main objective of this study was to determine differences in sperm recovered from the three segments of the epididymis, i.e., head, corpus and cauda, using routine measurements of sperm quality and DNA fragmentati...The main objective of this study was to determine differences in sperm recovered from the three segments of the epididymis, i.e., head, corpus and cauda, using routine measurements of sperm quality and DNA fragmentation assessment. There was a larger sperm concentration (P < 0.05) in the head (3.34 × 106 sperm/mL) compared with the corpus and cauda. The percentage of normal morphology was higher in the cauda but had lower motility (P < 0.05). The DNA fragmentation index was higher for sperm obtained from the head and body of the epididymis (P < 0.01) compared with the cauda. The DNA fragmentation index values were 12% higher (P < 0.01) using Wright stain compared with DAPI stain in sperm from the head and corpus of the epididymis, but similar in the cauda. Spermatobioscopy parameters match the maturation changes that occur in the epididymal tract with higher quality sperm being from the cauda, but with a lower concentration compared to sperm found in the head.展开更多
In this paper we present a set of numerical simulations designed to study the interaction process of HII molecular clouds. For the initial conditions we assume head-on and oblique collisions of binary identical clouds...In this paper we present a set of numerical simulations designed to study the interaction process of HII molecular clouds. For the initial conditions we assume head-on and oblique collisions of binary identical clouds placedadjacent to one another, with their surfaces just in contact. The colliding initial clouds are uniform density molecular gas spheres with rigid body rotation. The cloud initial conditions are chosen to favor its gravitational collapse as an isolated system. To study the effect of the self-gravity of the cloud in the collision process, we consider several models in which the approaching speed of the colliding clouds increases from zero up to several times the initial sound speed of the barotropic gas. We present the outcome of these collision models for several values of the impact parameter b, which depends on the initial radius of the cloud. We have explored the parameter space of the approaching velocity Vapp of the colliding clouds for configurations that may result in seeds for the formation of more complex systems. Such systems are expected to include filaments and gas clumps, where the star formation process is still possible despite the occurrence of the collision. We show hereby that collisions may have a major and favorable influence on the star formation process.展开更多
The differential cross section for an electron Raman scattering process in a semiconductor GaAs/AlGaAs double quantum well wire is calculated,and expressions for the electronic states are presented.The system is model...The differential cross section for an electron Raman scattering process in a semiconductor GaAs/AlGaAs double quantum well wire is calculated,and expressions for the electronic states are presented.The system is modeled by considering T = 0 K and also with a single parabolic conduction band,which is split into a subband system due to the confinement.The gain and differential cross-section for an electron Raman scattering process are obtained.In addition,the emission spectra for several scattering configurations are discussed,and interpretations of the singularities found in the spectra are given.The electron Raman scattering studied here can be used to provide direct information about the efficiency of the lasers.展开更多
The synthesis and the catalysis in the HDS of DBT reaction of nanostructured self-supported catalyst containing MoS2+x nanoplatelets have been investigated. Enhancement of higher activity observed in sulfide catalyst ...The synthesis and the catalysis in the HDS of DBT reaction of nanostructured self-supported catalyst containing MoS2+x nanoplatelets have been investigated. Enhancement of higher activity observed in sulfide catalyst sample (d) with respect to the ex situ and in situ references is more closely related to the morphology change of particles (nanoplatelets). In this work, we suggest that certain structures present in model catalysts maybe related to low dimensional structures and present a theoretical study of two MoS2 clusters (one made of 34 atoms/cluster and the second one made of 41 atoms/cluster), to these clusters seven sulfur atoms were randomly located at the surface of the sulfur layer, in order to simulate certain structures resembling arrow shaped nanoplatelets that were found in a High Resolution TEM analysis performed in some MoS2 samples. Additionally, one of the goals is to enquire about the electronic properties presented in such structures when the clusters terminated as Moor S-edge and if it could be correlated to the catalyst behavior of these compounds. To the 34 atoms/cluster Mo-edge yielded metallic behavior while the second cluster the 41 atoms/ cluster S-edge yielded a semiconductor behavior with a forbidden energy gap Eg of the order of @ 3.6 eV between the Valence and Conductions bands respectively. Moreover, to the same clusters enunciated formerly, when the sulfur atoms were located at the surface of the S-layer, for the first cluster (34 atoms/cluster) yielded a more metallic behavior, while the second one (41 atoms/cluster) yielded an isolator behavior. Our results agree with the experimental and theoretical results presented by several groups in different laboratories arriving to the conclusion that the S-Mo-S Mo-edge arrow heads structures could be responsible to the enhancement of the catalytic activity on the MoS2 studied samples.展开更多
We have evaluated the effects of intravitreal dobesilate, a synthetic fibroblast growth factor inhibitor, in patients with dry age-related macular degeneration, an inflammatory-related retinal disease without availabl...We have evaluated the effects of intravitreal dobesilate, a synthetic fibroblast growth factor inhibitor, in patients with dry age-related macular degeneration, an inflammatory-related retinal disease without available treatment up to date. 36 eyes from 36 patients with dry age-related macular degeneration were treated with a single intravitreal dobesilate injection. The end points were the improvement from baseline visual acuity and normalization of retinal histology at one month. Intravitreal dobesilate injection resulted in a significant improvement in functional and anatomical outcomes at one month after injection. Our results suggest that intravitreal dobesilate may increase the chance of visual acuity gain in dry age-related macular degeneration, even in cases with initial low vision. This study supports the findings of previously published case reports, regarding the short-term improvement in visual acuity by intravitreal dobesilate injection in different degenerative retinal diseases.展开更多
Five studies were conducted in order to produce less waste and economize the application of a CdCl2–Na3C6H5O7– KOH–H3BO3/NaOH/KCl–(NH2)2CS definite aqueous system in the chemical bath deposition of CdS thin films,...Five studies were conducted in order to produce less waste and economize the application of a CdCl2–Na3C6H5O7– KOH–H3BO3/NaOH/KCl–(NH2)2CS definite aqueous system in the chemical bath deposition of CdS thin films, as well as to generate supporting information helpful to explain the effects of varying certain parameters established for the use of this formulation. These studies are related to the utility of the pH 10 borate buffer, to the selection of the appropriateOH–concentration, commercial alkali, and reaction temperature, and to the reusing of the residual solution. These studies were conducted by means of optical characterization, pH measurements, energy consumption tests, and chemical analysis;and all possible implications were analyzed in detail and widely supported by the literature. It is observed that the addition of 5.0 mL of pH 10 borate buffer in the reaction solutions only causes a slight reduction in the pH value and, therefore, in the thickness of the resulted films. It is observed that a decrease in CdCl2 concentration causes an increase in the pH values, and when such reagent concentration is varied it is necessary to determine the pH value at which the best CdS films can be obtained;this indicates the existence of an optimum pH of deposition, depending on the used reagent concentrations. It is demonstrated that the use of KOH and NaOH is interchangeable, and the advantages of NaOH are evaluated in the context of hygroscopicity, CO2 absorption, purity, and price. It is observed that the energy consumption when depositing a determined film is lower at high temperatures, and it is concluded that the time and energy savings at high temperatures are undoubtedly advantages in the deposition process of CdS thin films. A formulation to recycle the residual solution is presented, which is very important for the reducing of residual volume, and, therefore, in the minimizing of the environmental impact. An indirect objective of this work is to generate interest in identifying those points that could be modified in other chemical formulations to minimize costs and waste.展开更多
Aim: Fibulins and ADAMTSs are two families of extracellular matrix proteins implicated in key functional and pathological processes. The fact that the fibulin-1 and ADAMTS-1 proteins interact raises new questions abou...Aim: Fibulins and ADAMTSs are two families of extracellular matrix proteins implicated in key functional and pathological processes. The fact that the fibulin-1 and ADAMTS-1 proteins interact raises new questions about the roles of these extracellular matrix proteins in modulating tumor progression. Herein, we described the functional implications of the interaction between fibulin-1 and ADAMTS-1 on the behavior of breast cancer cell lines. Methods: Fibulin-1 and ADAMTS-1 were exogenously expressed in MCF-7 and MDA-MB-231 cell lines to assay the effect of their interaction in cellular properties. Results: ADAMTS-1 expression exacerbates tumor effects in terms of proliferation, invasion and mammosphere formation. In contrast, the simultaneous expression of ADAMTS-1 and fibulin-1 impairs these effects. The analysis of the expression of both proteins in human breast cancer tissue arrays provides new insights into the complex roles of fibulin-1 and ADAMTS-1 in this type of tumor. ;Conclusion: Our results suggests that the interaction between ADAMTS-1 and fibulin-1 induces a pronounced anti-tumoral effect.展开更多
基金The authors acknowledge the support of the Division of Biological Science and Health of the University of Sonora for the Project USO313006744。
文摘This study aimed to characterize the physical-chemical and biological properties of pectin(PC)/chia seed mucilage(CM)membranes.PC/CM[100/0(control),80/20%,60/40%,and 40/60%w/w]membranes were prepared using the casting method.The membranes(PC/CM)were thin,yellow,lightly opaque(≈10%)and capable of blocking light UVB(between 66 at 52%).SEM analysis showed the presence of aggregates in the shape of a sphere(≈13μm)and ovoid(≈25μm).The proportion of 80/20 showed an increase in tensile strength(29%)and elastic modulus(19%)when compared to the control.FTIR analysis exhibited intermolecular interactions between PCPC,PC-CM,and CM-CM in the membranes.The thermal analysis(600°C)showed a slight improvement in the percentage of residual mass-loss of 3.31%(80/20)that control.The 40/60 membrane showed the lowest percentage of hemolysis(2.94%)but limited human albumin adsorption capacity.These results suggested that the blend PC/CM may be considered as a biomaterial for medical applications.
文摘Ischemic stroke is the most common type of cerebrovascular disease and is caused by an interruption of blood flow in the brain.In this disease,two different damage areas are identifying:the lesion core,in which cells quickly die;and the penumbra(surrounding the lesion core),in which cells are functionally weakened but may recover and restore their functions.The currently approved treatments for ischemic stroke are the recombinant tissue plasminogen activator and endovascular thrombectomy,but they have a short therapeutic window(4.5 and 6 hours after stroke onset,respectively)and a low percentage of stroke patients actually receive these treatments.Memantine is an approved drug for the treatment of Alzheimer's disease.Memantine is a noncompetitive,low affinity and use-dependent antagonist of N-methyl-D-aspartate glutamate receptor.Memantine has several advantages over developing a new drug to treat focal ischemic stroke,but the most important is that it has sufficient safe probes in preclinical models and humans,and if the preclinical studies provide more evidence about pharmacological actions in tissue protection and repair,this could help to increase the number of clinical trials.The present review summarizes the physiopathology of isquemic stroke and the pharmacological actions in neuroprotection and neuroplasticity of memantine in the post stroke stage of preclinical stroke models,to illustrate their potential to improve functional recovery in human patients.
文摘Background:Dry eye is a multifactor disease of the tear film and ocular surface that substantially affects quality of life.Case presentation:Dobesilate administered as eye drops was well tolerated and effective in treating both the objective signs and subjective symptoms of dry eye disease in this 2-week study.Conclusion:To the best of our knowledge,this is the first clinical report of using dobesilate in eye drops.Dobesilate may provide a novel approach to treating drying diseases of the eye.
文摘Vitreous hemorrhages are important clinical manifestations of proliferative diabetic retinopathy. Non-cleared vitreous hemorrhages could lead to hemosiderosis bulbi and glaucoma. Here, we describe the case of a type 2 diabetic patient presenting anterior segment and vitreous hemorrhages that resolved three days after treatment with a single intravitreal injection of dobesilate.
文摘The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of 100 and 300 mg·L-1, respectively. Both metal ions had insignificant inhibitory effect over the metabolism of the biomass, specifically, on substrate consumption and production of volatile fatty acids (VFAs). The microstructural characterization of the biofilm by Scanning Electron Microscopy showed no effect on the morphology of the microorganisms after the metals treatment. Copper and iron removal was also measured in the reactor, achieving a breakthrough time of 3 days, during which removal efficiencies were higher than 90%. It was also observed that the biomass had a greater affinity for copper. The results indicate that acidogenic biomass can be used effectively as a sorbent agent. The pollution of river-streams with heavy metals—mainly copper and iron—was one of the most compelling motivations for conducting this investigation. The San Pedro River Basin, a trans-boundary river that originates near the mining town of Cananea, Sonora, México, and flows to Arizona, USA, exemplifies this environmental issue.
文摘Bacterial infections are highly prevalent and a frequent cause of hospitalization and short-term mortality in patients with cirrhosis. Due to their negative impact on survival, antibiotic prophylaxis for bacterial infections in high-risk subgroups of patients with cirrhosis has been the standard of care for decades. Patients with prophylaxis indications include those at risk for a first episode of spontaneous bacterial peritonitis(SBP) due to a low ascitic fluid protein count and impaired liver and kidney function, patients with a prior episode of SBP and those with an episode of gastrointestinal bleeding. Only prophylaxis due to gastrointestinal bleeding has a known and short-time duration. All other indications imply longlasting exposure to antibiotics-once the threshold requirement for initiating prophylaxis is met-without standardized criteria for re-assessing antibiotic interruption. Despite the fact that the benefit of antibiotic prophylaxis in reducing bacterial infections episodes and mortality has been thoroughly reported, the extended use of antibiotics in patients with cirrhosis has also had negative consequences, including the emergence of multi-drug resistant bacteria.Currently, it is not clear whether restricting the use of broad and fixed antibiotic regimens, tailoring the choice of antibiotics to local bacterial epidemiology or selecting non-antibiotic strategies will be the preferred antibiotic prophylaxis strategy for patients with cirrhosis in the future.
文摘The extraction of bioactive compounds has become one of the most interesting areas of modern chemistry.For therapeutic reasons,it´s important to obtain antimicrobial agents from natural origin.The objective of the present study was to determine the inhibitory effect of ethanolic extract of basil(Ocimum basilicum L.var.Red Rubin)subjected to different concentrations of potassium(K^(+))on the activity of three bacterial strains that are pathogens in humans.Susceptibility was evaluated by inhibition surface and these results were compared to two antibiotics:Gentamicin(GE)and Ciprofloxacin(CPF)for their efficacy against each bacterial strain.Analyzed variables presented significant difference(p≤0.05).According to the results,basil extract evaluated showed positive antibacterial activity against the three strains of Pseudomonas aeruginosa,Listeria monocytogenes and Staphylococcus aureus on Mueller Hinton agar.It was observed highest inhibition areas of different diameters(15.3 mm,21.3 mm and 21.6 mm respectively)when the extract used was obtained from the plants with the highest concentration of potassium(13 mmol L-1).These values were even superior to the highest values showed on the treatments with the antibiotic gentamicin.
文摘Animal protein foods are undoubtedly among the most concentrated source of essential amino acids (AA) for the human diet. However, their high prices and diseases associated to their excessive consumption have fomented the consumption of other alternative sources of animal proteins such as those from marine or aquatic species. Sonora is a well recognized producer of animal foods in Mexico, both terrestrial and aquatic. In this study, the protein quality evaluation of these animal food sources, highly produced and consumed in Sonora, is proposed, using in-vitro methodologies. Four different species, from each aquatic and terrestrial origin, were selected. Samples of lean muscle were used in all cases. Various in-vitro methodologies for protein quality evaluation were selected, alternatives to the animal bioassays: % digestibility, Total amino acid analyses (HPLC), PDCAAS, computerized PER calculations (C-PER and DC-PER) and total collagen contents. % in-vitro digestibility presented significant differences among samples from terrestrial species, but muscle from aquatic species did not showed significant differences. All sources of proteins, both aquatic and terrestrial proved to be rich sources of essential amino acids. PDCAAS was unable to establish significant differences in protein quality among sources of protein from different origin. Both methods C-PER and DC-PER were more exact in their results and were able to detect significant differences among samples of different origin. An important finding was the great difference in the total collagen content between aquatic and terrestrial sources of proteins, where terrestrial muscle proteins had almost 10-time more collagen than aquatic protein sources. However, these collagen contents did not seem to have a significant influence in the protein quality of these animal proteins. These muscle proteins, from both aquatic and terrestrial species, confirmed to have a high protein quality and some of the in-vitro methodologies used in this study represent a valuable alternative to the animal bioassays.
文摘Cereal crop improvement programmes involve the analysis of a great number of lines every year;the availability of a simple, rapid method that would allow the identification of a trait in the early stages of plant development would facilitate the selection process. This work reports two experiments involving the germination of seeds in Petri dishes, performed to study the effect of water deficit on the growth of barley coleoptiles. In one experiment water stress was induced by allowing evaporation from the Petri dishes;in the other water stress was achieved by adding polyethylene glycol 6000. The growth of the control coleoptiles was greater than that of the treatment coleoptiles in all cases, but with differences between the different genotypes. A significant correlation (P < 0.01) was found between the relative growth of the coleoptiles and turgor maintenance in the seedlings. Significant correlations were also seen between the relative growth of the coleop-tiles and the osmotic adjustment of the flag leaf (P < 0.05) and the grain weight (P < 0.01) in adult plants. The genotypes that showed the greatest relative growth also showed the greatest capacity for osmotic adjustment in the flag leaf and produced the greatest yields in experiments with adult plants. The results indicate that the growth of coleoptiles subjected to water deficit could be used as a selection criterion in breeding programmes designed to improve the tolerance of barley to drought.
文摘Objective: It is in order to estimate the prevalence and incidence of HIV, the frequency of sexual risk behaviors, and perceptions of available resources to prevent and treat HIV among crack users in the San Salvador Metropolitan Area. Methods: We conducted a survey of 420 crack users by using respondent-driven sampling to measure demographic characteristics, the quantity and frequency of drug use, history of STIs, including HIV, and experiences with organizations which provide prevention and treatment of HIV. Each participant offered a free and voluntary HIV test and was asked permission to share the results of the test with the study. Bernoullian modeling was used to estimate the prevalence and incidence of HIV among heterosexual males in this population. Results: The estimated prevalence was 7% (95% CI: 2.3% -9.8%) among participants who agreed to take the test and share the results, and 4.9% (95% CI: 2.8% -7.8%) assuming that those who did not take the test or share results were seronegative. Participants reported a high frequency of sexual risk behaviors. In addition, participants were reported to have little knowledge of organizations to prevent or treat HIV/AIDS;58% had never taken an HIV test prior to survey administration. Conclusions: Crack users in San Salvador are at high risk for HIV acquisition. HIV prevention interventions are urgently needed, especially interventions increasing access to HIV testing and prevention.
文摘Urolithiasis (UL) is an endemic disease in Southeastern, Mexico. In order to evaluate the association of I550V polymorphism in the hNaDC-1 gene with risk for hypocitraturia and/or for UL;139 adults with UL and 132 adults without UL, were included under a case-control association study. Citrate levels in 24-h urine were quantified (citraturia). The polymorphism I550V-hNaDC-1 was determined by PCR-RFLP. Statistical analysis was performed using the STATA10.2 software. Comparison of genotype and allele frequencies between subjects with and without UL showed significant differences for genotype bb (OR = 2.34, CI: 1.19-4.59, p = 0.01) and for allele b (OR = 1.62, CI: 1.15-2.28, p = 0.005), suggesting an association with the risk for UL. Comparison of genotype and allele frequencies between subjects with hypocitraturia and subjects with normocitraturia, did not show any significant difference (p > 0.05), suggesting that this polymorphism is not associated with the risk of hypocitraturia. Interestingly, the risk for UL was increased due to an additive effect of hypocitraturia with the genotype bb (OR = 6.6, CI: 2.38-18.28, p = 0.0002) or with the allele b (OR: 4.2, CI = 2.52-6.97,
文摘Despite the breadth of knowledge about malaria, its transmission, preventive measures and available treatments and its difficulty in controlling the vector and the rapid spread of resistance to current drugs, there is a stimulus to develop new research looking for active molecules. The phytochemical studies of the active extract confirmed the presence of alkaloids, flavonoids, coumarins, tannins, reducing compounds, anthocyanins, terpenes, triterpenes and steroids. In the present work, it was possible to isolate a mixture of isoquinolinic alkaloids from the tender leaves of Nectandra membranacea (Laureaceae) with antimalarial activity. The mixture composed of (-) - gliazovine and (+) - aplogliazovine showed an IC50 value of 32.18 μg/mL against the P. berghei NK65 strain. It is important to continue with these studies and their chemical components isolated from N. membranacea that could be used as an alternative the treatment of malaria.
文摘Candidiasis is the most common opportunistic fungal infection in HIV patients, and its presence is ascribed mainly to the persistence of the original infecting strain. The latter might acquire genetic variations during interaction with the host, reflecting the adaptation of the strain. Here, we report the case of a 32-year-old man complaining of asthenia, irregular hyperpyrexia, and dry cough, who was admitted to the emergency unit. Laboratory examination showed positivity for HIV. Dark violet macular lesions and ulcerated lesions with verrucous erosion were observed at the tip of the nose, whereas an ulcer without exudates was noted in the pubic region. Candida albicans was recovered from the skin by scraping these lesions. Cultures from the bronchoalveolar lavage (BAL) were negative for bacteria and opportunistic fungi but were positive for Candida albicans. The isolates from the skin and BAL were typed by PCR-RFLP and Candida albicans was identified. Analysis by microsatellite length polymorphisms, established that the pubic isolate was a genetic variant of the isolate from the nose and mouth. This suggested a microevolutionary event. Despite clinical support, the patient died of multiple organ failure.
文摘The main objective of this study was to determine differences in sperm recovered from the three segments of the epididymis, i.e., head, corpus and cauda, using routine measurements of sperm quality and DNA fragmentation assessment. There was a larger sperm concentration (P < 0.05) in the head (3.34 × 106 sperm/mL) compared with the corpus and cauda. The percentage of normal morphology was higher in the cauda but had lower motility (P < 0.05). The DNA fragmentation index was higher for sperm obtained from the head and body of the epididymis (P < 0.01) compared with the cauda. The DNA fragmentation index values were 12% higher (P < 0.01) using Wright stain compared with DAPI stain in sperm from the head and corpus of the epididymis, but similar in the cauda. Spermatobioscopy parameters match the maturation changes that occur in the epididymal tract with higher quality sperm being from the cauda, but with a lower concentration compared to sperm found in the head.
文摘In this paper we present a set of numerical simulations designed to study the interaction process of HII molecular clouds. For the initial conditions we assume head-on and oblique collisions of binary identical clouds placedadjacent to one another, with their surfaces just in contact. The colliding initial clouds are uniform density molecular gas spheres with rigid body rotation. The cloud initial conditions are chosen to favor its gravitational collapse as an isolated system. To study the effect of the self-gravity of the cloud in the collision process, we consider several models in which the approaching speed of the colliding clouds increases from zero up to several times the initial sound speed of the barotropic gas. We present the outcome of these collision models for several values of the impact parameter b, which depends on the initial radius of the cloud. We have explored the parameter space of the approaching velocity Vapp of the colliding clouds for configurations that may result in seeds for the formation of more complex systems. Such systems are expected to include filaments and gas clumps, where the star formation process is still possible despite the occurrence of the collision. We show hereby that collisions may have a major and favorable influence on the star formation process.
文摘The differential cross section for an electron Raman scattering process in a semiconductor GaAs/AlGaAs double quantum well wire is calculated,and expressions for the electronic states are presented.The system is modeled by considering T = 0 K and also with a single parabolic conduction band,which is split into a subband system due to the confinement.The gain and differential cross-section for an electron Raman scattering process are obtained.In addition,the emission spectra for several scattering configurations are discussed,and interpretations of the singularities found in the spectra are given.The electron Raman scattering studied here can be used to provide direct information about the efficiency of the lasers.
文摘The synthesis and the catalysis in the HDS of DBT reaction of nanostructured self-supported catalyst containing MoS2+x nanoplatelets have been investigated. Enhancement of higher activity observed in sulfide catalyst sample (d) with respect to the ex situ and in situ references is more closely related to the morphology change of particles (nanoplatelets). In this work, we suggest that certain structures present in model catalysts maybe related to low dimensional structures and present a theoretical study of two MoS2 clusters (one made of 34 atoms/cluster and the second one made of 41 atoms/cluster), to these clusters seven sulfur atoms were randomly located at the surface of the sulfur layer, in order to simulate certain structures resembling arrow shaped nanoplatelets that were found in a High Resolution TEM analysis performed in some MoS2 samples. Additionally, one of the goals is to enquire about the electronic properties presented in such structures when the clusters terminated as Moor S-edge and if it could be correlated to the catalyst behavior of these compounds. To the 34 atoms/cluster Mo-edge yielded metallic behavior while the second cluster the 41 atoms/ cluster S-edge yielded a semiconductor behavior with a forbidden energy gap Eg of the order of @ 3.6 eV between the Valence and Conductions bands respectively. Moreover, to the same clusters enunciated formerly, when the sulfur atoms were located at the surface of the S-layer, for the first cluster (34 atoms/cluster) yielded a more metallic behavior, while the second one (41 atoms/cluster) yielded an isolator behavior. Our results agree with the experimental and theoretical results presented by several groups in different laboratories arriving to the conclusion that the S-Mo-S Mo-edge arrow heads structures could be responsible to the enhancement of the catalytic activity on the MoS2 studied samples.
文摘We have evaluated the effects of intravitreal dobesilate, a synthetic fibroblast growth factor inhibitor, in patients with dry age-related macular degeneration, an inflammatory-related retinal disease without available treatment up to date. 36 eyes from 36 patients with dry age-related macular degeneration were treated with a single intravitreal dobesilate injection. The end points were the improvement from baseline visual acuity and normalization of retinal histology at one month. Intravitreal dobesilate injection resulted in a significant improvement in functional and anatomical outcomes at one month after injection. Our results suggest that intravitreal dobesilate may increase the chance of visual acuity gain in dry age-related macular degeneration, even in cases with initial low vision. This study supports the findings of previously published case reports, regarding the short-term improvement in visual acuity by intravitreal dobesilate injection in different degenerative retinal diseases.
文摘Five studies were conducted in order to produce less waste and economize the application of a CdCl2–Na3C6H5O7– KOH–H3BO3/NaOH/KCl–(NH2)2CS definite aqueous system in the chemical bath deposition of CdS thin films, as well as to generate supporting information helpful to explain the effects of varying certain parameters established for the use of this formulation. These studies are related to the utility of the pH 10 borate buffer, to the selection of the appropriateOH–concentration, commercial alkali, and reaction temperature, and to the reusing of the residual solution. These studies were conducted by means of optical characterization, pH measurements, energy consumption tests, and chemical analysis;and all possible implications were analyzed in detail and widely supported by the literature. It is observed that the addition of 5.0 mL of pH 10 borate buffer in the reaction solutions only causes a slight reduction in the pH value and, therefore, in the thickness of the resulted films. It is observed that a decrease in CdCl2 concentration causes an increase in the pH values, and when such reagent concentration is varied it is necessary to determine the pH value at which the best CdS films can be obtained;this indicates the existence of an optimum pH of deposition, depending on the used reagent concentrations. It is demonstrated that the use of KOH and NaOH is interchangeable, and the advantages of NaOH are evaluated in the context of hygroscopicity, CO2 absorption, purity, and price. It is observed that the energy consumption when depositing a determined film is lower at high temperatures, and it is concluded that the time and energy savings at high temperatures are undoubtedly advantages in the deposition process of CdS thin films. A formulation to recycle the residual solution is presented, which is very important for the reducing of residual volume, and, therefore, in the minimizing of the environmental impact. An indirect objective of this work is to generate interest in identifying those points that could be modified in other chemical formulations to minimize costs and waste.
基金the Instituto Asturiano de Odontología(IAO).Mohamedi Y is recipient of a fellowship from the FICYT,"Fundación para el Fomento en Asturias de la Investigación Científica Aplicaday la Tecnología"Tania Fontanil is recipient of a contract from the"Departamento de Investigación de Clínica Ordonez(Oviedo)"
文摘Aim: Fibulins and ADAMTSs are two families of extracellular matrix proteins implicated in key functional and pathological processes. The fact that the fibulin-1 and ADAMTS-1 proteins interact raises new questions about the roles of these extracellular matrix proteins in modulating tumor progression. Herein, we described the functional implications of the interaction between fibulin-1 and ADAMTS-1 on the behavior of breast cancer cell lines. Methods: Fibulin-1 and ADAMTS-1 were exogenously expressed in MCF-7 and MDA-MB-231 cell lines to assay the effect of their interaction in cellular properties. Results: ADAMTS-1 expression exacerbates tumor effects in terms of proliferation, invasion and mammosphere formation. In contrast, the simultaneous expression of ADAMTS-1 and fibulin-1 impairs these effects. The analysis of the expression of both proteins in human breast cancer tissue arrays provides new insights into the complex roles of fibulin-1 and ADAMTS-1 in this type of tumor. ;Conclusion: Our results suggests that the interaction between ADAMTS-1 and fibulin-1 induces a pronounced anti-tumoral effect.