The effect on the performance of a dynamic navigation system of superimposing a standard tessellation language (STL) file obtained with an intraoral scan on a cone beam computer tomograph (CBCT). An experimental in vitro study.

OBJECTIVES: To compare the accuracy and operative time of implant placement using a dynamic computer assisted implant surgery (dCAIS) system based on a cone beam computer tomography (CBCT) image, with and without superimposing a standard tessellation language (STL) file of an intraoral scan of the patient. METHODS: Ten identical resin models simulating an upper maxilla with posterior edentulism were assigned to two groups. In the CBCT+STL group, a CBCT file and an intraoral STL file were superimposed and used for registration; in the CBCT group, registration was performed using CBCT images. Six implants were placed in each model using the Navident® dynamic navigation system. Anatomy registration was performed by tracing fiducial points on the CBCT or STL image, depending on the group. Preoperative and postoperative CBCT images were overlaid to assess implant placement accuracy. RESULTS: Sixty implants were analyzed (30 implants in each group). 3D platform deviation was significantly lower (mean difference (MD): 0.17 mm; 95 % confidence interval (CI): 0.01 to 0.23; P = 0.039) in the CBCT+STL group (mean: 0.71 mm; standard deviation (SD): 0.29) than in the CBCT group (mean: 0.88 mm; SD: 0.39). The remaining accuracy outcome variables (angular deviation MD: -0.01; platform lateral deviation MD: 0.08 mm; apex global MD: 0.01 mm; apex depth MD: 0.33 mm) and surgery time (MD: 3.383 min.) were similar in both groups (p > 0.05). CONCLUSIONS: The introduction of an intraoral scan (STL) seems to reduce deviations slightly in dental implant placement with dCAIS systems. However, the clinical repercussion of this improvement is questionable. CLINICAL SIGNIFICANCE: Superimposing an intraoral scan on the CBCT image does not seem to increase the accuracy of dCAIS systems but can be useful when radiographic artifacts are present.

Peri-implantitis in patients without regular supportive therapy: Prevalence and risk indicators.

OBJECTIVES: To determine the prevalence of peri-implant diseases in patients treated in a university setting without a regular peri-implant supportive therapy schedule, and to identify the risk indicators associated with peri-implantitis. MATERIAL AND METHODS: A retrospective cohort study was made of patients with dental implants with at least 12 months of functional loading who did not receive regular peri-implant supportive therapy. Patient- and implant-related variables were retrieved, and clinical and radiological examinations were performed. Descriptive and bivariate analyses and multilevel logistic regression analyses were performed to identify factors associated with peri-implantitis. RESULTS: A total of 213 implants in 88 patients were analyzed. The patient-level prevalence of peri-implantitis and peri-implant mucositis was 26.1% (95%CI: 16.7%-35.5%) and 44.3% (95%CI: 34.0%-54.6%), respectively. Peri-implant diseases were significantly more frequent when the width of the keratinized mucosa was < 2 mm (OR = 5.26; 95%CI: 1.24-22.26; p = 0.024), and when there was 12 month post-loading bone loss (OR = 2.96; 95%CI: 1.35-6.52; p = 0.007). CONCLUSIONS: Peri-implantitis is a common finding in patients without regular peri-implant supportive therapy (prevalence 16.7-35.5%). A thin peri-implant keratinized mucosa (< 2 mm) and a higher degree of bone remodeling after loading seem to be the main risk factors for peri-implantitis in this patient profile. CLINICAL RELEVANCE: Patients who do not engage in supportive peri-implant maintenance have a higher risk of peri-implantitis. A thin keratinized mucosa and bone loss during the first year of loading are predisposing factors for peri-implantitis.

Fungi's Swiss Army Knife: Pleiotropic Effect of Melanin in Fungal Pathogenesis during Cattle Mycosis.

Fungal threats to public health, food security, and biodiversity have escalated, with a significant rise in mycosis cases globally. Around 300 million people suffer from severe fungal diseases annually, while one-third of food crops are decimated by fungi. Vertebrate, including livestock, are also affected. Our limited understanding of fungal virulence mechanisms hampers our ability to prevent and treat cattle mycoses. Here we aim to bridge knowledge gaps in fungal virulence factors and the role of melanin in evading bovine immune responses. We investigate mycosis in bovines employing a PRISMA-based methodology, bioinformatics, and data mining techniques. Our analysis identified 107 fungal species causing mycoses, primarily within the Ascomycota division. Candida, Aspergillus, Malassezia, and Trichophyton were the most prevalent genera. Of these pathogens, 25% produce melanin. Further research is required to explore the involvement of melanin and develop intervention strategies. While the literature on melanin-mediated fungal evasion mechanisms in cattle is lacking, we successfully evaluated the transferability of immunological mechanisms from other model mammals through homology. Bioinformatics enables knowledge transfer and enhances our understanding of mycosis in cattle. This synthesis fills critical information gaps and paves the way for proposing biotechnological strategies to mitigate the impact of mycoses in cattle.

Axes of social inequities in COVID-19 clinical trials: A systematic review.

Objective: The representativeness of participants is crucial to ensure external validity of clinical trials. We focused on the randomized clinical trials which assessed COVID-19 vaccines to assess the reporting of age, sex, gender identity, race, ethnicity, obesity, sexual orientation, and socioeconomic status in the results (description of the participants' characteristics, loss of follow-up, stratification of efficacy and safety results). Methods: We searched the following databases for randomized clinical trials published before 1st February 2022: PubMed, Scopus, Web of Science, and Excerpta Medica. We included peer-reviewed articles written in English or Spanish. Four researchers used the Rayyan platform to filter citations, first reading the title and abstract, and then accessing the full text. Articles were excluded if both reviewers agreed, or if a third reviewer decided to discard them. Results: Sixty three articles were included, which assessed 20 different vaccines, mainly in phase 2 or 3. When describing the participants' characteristics, all the studies reported sex or gender, 73.0% race, ethnicity, 68.9% age groups, and 22.2% obesity. Only one article described the age of participants lost to follow-up. Efficacy results were stratified by age in 61.9%, sex or gender in 26.9%, race and/or, ethnicity in 9.5%, and obesity in 4.8% of the articles. Safety results were stratified by age in 41.0%, and by sex or gender in 7.9% of the analysis. Reporting of gender identity, sexual orientation or socioeconomic status of participants was rare. Parity was reached in 49.2% of the studies, and sex-specific outcomes were mentioned in 22.9% of the analysis, most of the latter were related to females' health. Conclusions: Axes of social inequity other than age and sex were hardly reported in randomized clinical trials that assessed COVID-19 vaccines. This undermines their representativeness and external validity and sustains health inequities.

Criminality in Huntington Disease.

Background and Objectives: Huntington disease (HD) is an inherited neurodegenerative condition associated with varying degrees of motor, cognitive, and behavioral abnormalities. Although aggression, irritability, lack of insight, and poor impulse are well-recognized nonmotor manifestations of the disease, very little is known about their association with criminality, which is broadly defined as acts that are punishable by law. Methods: We explored the prevalence of criminality in patients with HD seen between January 1, 2017, and December 31, 2021, within a large academic medical center in the state of Illinois. To determine rates of criminality, we examined "criminal behavior" (defined as illegal actions that do not necessarily lead to criminal prosecution) through a retrospective medical record review of keywords or phrases related to criminality. We also examined "crime" (defined as the presence of a criminal record) in this same sample of patients through a search of official publicly available online databases from the state of Illinois and the federal government. Results: Of the 210 patients included, 97 (46.2%) had criminal behavior documented in their medical records. Based on public database information, 89 patients (42.4%) had a criminal record and 26 patients (12.4%) had been arrested. Traffic violations were committed by 94.4% of the cohort and were the most common infractions. Most of these violations were petty offenses and only punishable by fines. Physical aggression toward caregivers was the most common criminal behavior identified in medical records. This tended to occur in advance stages of the disease and rarely led to criminal charges. Crime occurred at any point in the disease course of HD, including before and after the development of clinical signs and the formal diagnosis of HD. Discussion: The presence of criminality was not infrequent in our cohort, but rarely did this result in criminal charges and rarely did these charges result in arrests or incarcerations. Discussions surrounding driving safety and management of physical aggression toward caregivers should be part of regular outpatient visits with patients with HD. Ultimately, it is unknown whether criminality is a common feature of HD, and assessments need to be developed to determine its true prevalence.

Clinical report and fractographic analysis of a fractured partial laminate veneer.

Ceramic partial laminate veneers represent a conservative option for the correction of morphological abnormalities, diastemas, and fractured anterior teeth, with minimal or no tooth preparation. The present clinical report describes the use of a partial laminate veneer to correct the shape of a maxillary right central incisor to match the restoration of the more damaged adjacent tooth. The failure of the partial laminate veneer after only 18 months was analyzed using a systematic fractographic approach, identifying critical considerations that should be addressed when providing this type of restoration.

Efficacy of the use of chondroitin sulphate and glucosamine for the treatment of temporomandibular joint dysfunction: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the efficacy of chondroitin sulfate (CS) and glucosamine (GS), the most relevant drugs of "Symptomatic Slow Acting Drug for Osteoarthritis" (SYSADOA), in the functional and symptomatic improvement of temporomandibular dysfunction. Although, controversy exists regarding their benefit. METHODS: An electronic search was conducted to retrieve randomized controlled clinical trials (RCTs). The risk of bias assessment was evaluated using the Cochrane Collaboration's tool. Data were meta-analyzed with a random effect model whenever possible. RESULTS: Three RCTs were included. Qualitative results showed a decrease in pain, joint noise, and inflammatory biomarkers in synovial fluid and an improvement in maximum mouth opening without significant adverse effects. Meta-analysis showed a significant increase in maximum mouth opening with the use of CS-GS (p = 0.19). No statistically significant differences were found in pain reduction compared to tramadol. CONCLUSION: CS-GS is effective and safe in the symptomatic and functional improvement of patients with TMD.

Midline diastema closure using a lithium disilicate glass ceramic fragment: increased long-term color stability"

ABSTRACT: Nowadays, maxillary midline diastema (MMD) can be treated with different multidisciplinary approaches. When restorative dentistry is needed, glass-matrix ceramic materials is one of the best choices, since they present good optical behavior and high survival rates in the anterior dentition. To obtain an adequate interphase, and color integration are one of the main restorative goals, and for that purpose, specific finishing and polishing procedures must be employed to avoid staining and ensure the restoration's color stability. In the case report presented in this article, a single lithium disilicate ceramic fragment was performed to close a MMD produced by the shape alteration of one of the maxillary central incisors. Also, the finishing and polishing procedure is discussed.

Lateral indentation of a thin elastic film.

Indentation is a standard, widely used technique in mechanical assays and theoretical analysis. It unveils the fundamental modes of deformation and predicts the response of the material under more complex loads. Here we present an experimental setup for testing thin-film materials by studying the lateral indentation of a narrow opening cut into a film, triggering a cascade of buckling events. The force response F is dominated by bending and stretching effects for small displacements and slowly varies with indenter displacement F ∼ d2/5, to finally reach a wrinkled state that results in a robust nonlinear asymptotic relation, F ∼ d4. Experiments with films of various thicknesses and material properties, and numerical simulations confirm our analysis and help to define an order parameter that accounts for the different response regimes observed in experiments and simulations.

A Visual Approach to Measure Cloth-Body and Cloth-Cloth Friction.

Measuring contact friction in soft-bodies usually requires a specialised physics bench and a tedious acquisition protocol. This makes the prospect of a purely non-invasive, video-based measurement technique particularly attractive. Previous works have shown that such a video-based estimation is feasible for material parameters using deep learning, but this has never been applied to the friction estimation problem which results in even more subtle visual variations. Because acquiring a large dataset for this problem is impractical, generating it from simulation is the obvious alternative. However, this requires the use of a frictional contact simulator whose results are not only visually plausible, but physically-correct enough to match observations made at the macroscopic scale. In this paper, which is an extended version of our former work A. H. Rasheed, V. Romero, F. Bertails-Descoubes, S. Wuhrer, J.-S. Franco, and A Lazarus, "Learning to measure the static friction coefficient in cloth contact," in Proc. IEEE/CVF Conf. Comput. Vis. Pattern Recognit., 2020, pp. 9909-9918, we propose to our knowledge the first non-invasive measurement network and adjoining synthetic training dataset for estimating cloth friction at contact, for both cloth-hard body and cloth-cloth contacts. To this end we build a protocol for validating and calibrating a state-of-the-art frictional contact simulator, in order to produce a reliable dataset. We furthermore show that without our careful calibration procedure, the training fails to provide accurate estimation results on real data. We present extensive results on a large acquired test set of several hundred real video sequences of cloth in friction, which validates the proposed protocol and its accuracy.

Effective In Vitro Control of Two Phytopathogens of Agricultural Interest Using Cell-Free Extracts of Pseudomonas fluorescens and Chitosan.

A biofungicide is a natural product that can be derived from various sources such as, among others, microorganisms, higher plants, animal products, phytochemicals, semiochemicals, and antagonist microorganisms. One of the most important approaches for the production of biofungicides is the combination of biocontrol agents. This study showed the inhibition growth of Alternaria alternata and Fusarium solani treated with cell-free extracts of P. fluorescens. Using thin-layer chromatography and plate assays it was also demonstrated that the cell-free extracts of P. fluorescens contained siderophores and derivates of 4-diacetylphloroglucinol and phenazine. Moreover, the combination of cell-free extracts of P. fluorescens and chitosan [50-1.5% (v/v)] had a synergistic effect since they notably inhibited the mycelial growth of A. altenata and F. solani. Various morphological alterations to the mycelia and conidia of the treated fungi as a result of this combination were also observed. The present study could be a starting point to control other fungal phytopathogens using different cell-free extracts and chitosan as biocontrol agents.

[MIA 2021, Comprehensive Asthma Management. Guidelines for Mexico]. / MIA 2021, Manejo Integral del Asma. Lineamientos para México.

BACKGROUND: Asthma continues to be one of the most frequent chronic respiratory diseases in our country. New methods for diagnosis and treatment have been described; accordingly, the international guidelines were renewed. OBJECTIVE: To create a national platform for the development of updated guidelines, solidly based on evidence: Comprehensive Asthma Management (Spanish acronym: MIA). METHODS: MIA uses the ADAPTE method. The MIA development group consists of experts in pulmonology-allergology-methodology and representatives of 13 institutions and societies of specialties that manage asthma. The international reference guidelines (selected with AGREE-II): GINA 2020, GEMA 5.0, BTS/SIGN 2019 and ATS/ERS consensus document 2014-2019 on severe asthma. MIA covers suspected asthma, diagnosis, treatment, and special groups. Key clinical questions were formulated on treatment steps 1-3, biomarkers and severe asthma. RESULTS: Based on evidence, safety, cost and local reality, the core group developed responses. Through a Delphi process the broad MIA development group suggested adjustments until consensus was reached. CONCLUSION: A document was generated with multiple figures and algorithms, solidly based on evidence about asthma management, adjusted for Mexico with a broad base among different societies that participated in its development. It does not include guidelines for acute asthma.

Antecedentes: El asma sigue siendo una patología respiratoria crónica frecuente en México. Se han descrito nuevos métodos para el diagnóstico y tratamiento conforme se renuevan las guías internacionales. Objetivo: Crear la plataforma nacional Manejo Integral del Asma (MIA), para el desarrollo de lineamientos actualizados con base en evidencia. Métodos: Se utilizó el método ADAPTE. El grupo de desarrollo de MIA estuvo integrado por expertos en neumología, alergología y metodología y representantes de 13 instituciones y sociedades de especialidades que manejan asma. Las guías internacionales de referencia (seleccionadas con AGREE-II) fueron GINA 2020, GEMA 5.0, BTS/SIGN 2019 y consenso ATS/ERS 2014-2019. En MIA se aborda sospecha de asma, diagnóstico, tratamiento y grupos especiales. Se formularon preguntas clínicas clave sobre tratamiento en los pasos 1 a 3, biomarcadores y asma grave. Resultados: Con base en evidencia, seguridad, costo y realidad local, el grupo nuclear desarrolló respuestas. Mediante proceso Delphi, el grupo amplio de desarrollo sugirió ajustes hasta que se logró el consenso. Conclusión: El documento generado contiene múltiples figuras y algoritmos, está sólidamente basado en evidencia acerca del manejo del asma y fue ajustado para México con participación de diferentes sociedades para su desarrollo; no se incluyeron lineamientos para la crisis asmática.

A systematic review and meta-analysis on the effectiveness of xenograft to prevent periodontal defects after mandibular third molar extraction / Una revisión sistemática y un metanálisis sobre la eficacia del xenoinjerto para prevenir defectos periodontales después de la extracción del tercer molar mandibular

Background: To evaluate the use of guided bone regeneration with xenograft to prevent periodontal defect in thedistal aspect of the second molar after the surgical removal of the mandibular third molar.Material and Methods: Three electronic databases (Pubmed, Cochrane Library and Scopus) were searched inApril 2020. Randomized clinical trials in non-smokers and healthy patients, with at least six months follow-up, comparing periodontal probing depth, clinical attachment level, alveolar bone level and adverse events wereselected by two independent investigators. The risk of bias assessment of the selected studies was evaluated bymeans of the Cochrane Collaboration’s Tool. Finally, a meta-analysis of the outcomes of interest was performed.Results: Despite 795 articles were found in the initial search, only three randomized controlled clinical trials wereincluded. Pooled results favoured the use of the xenograft plus collagen membrane over the spontaneous healingin terms of periodontal probing depth gain (MD=2.36; 95% CI 0.69 to 4.03; P=0.005) and clinical attachment levelgain (MD=2.52; 95% CI 0.96 to 4.09; P=0.002). No other statistically significant differences were found.Conclusions: Within the limitations of the present review, the xenograft plus collagen membrane exhibited betterperiodontal results than spontaneous healing without increasing postoperative complications. However, future well-designed studies with larger samples are required to confirm our results.(AU)

Impact of Arterial Stiffness on All-Cause Mortality in Patients Hospitalized With COVID-19 in Spain.

Older age and cardiovascular comorbidities are well-known risk factors for all-cause mortality in patients with coronavirus disease 2019 (COVID-19). Hypertension and age are the 2 principal determinants of arterial stiffness (AS). This study aimed to estimate AS in patients with COVID-19 requiring hospitalization and analyze its association with all-cause in-hospital mortality. This observational, retrospective, multicenter cohort study analyzed 12 170 patients admitted to 150 Spanish centers included in the SEMI-COVID-19 Network. We compared AS, defined as pulse pressure ≥60 mm Hg, and clinical characteristics between survivors and nonsurvivors. Mean age was 67.5 (±16.1) years and 42.5% were women. Overall, 2606 (21.4%) subjects died. Admission systolic blood pressure (BP) <120 and ≥140 mm Hg was a predictor of higher all-cause mortality (23.5% and 22.8%, respectively, P<0.001), compared with systolic BP between 120 and 140 mm Hg (18.6%). The 4379 patients with AS (36.0%) were older and had higher systolic and lower diastolic BP. Multivariate analysis showed that AS and systolic BP <120 mm Hg significantly and independently predicted all-cause in-hospital mortality (adjusted odds ratio [ORadj]: 1.27, P=0.0001; ORadj: 1.48, P=0.0001, respectively) after adjusting for sex (males, ORadj: 1.6, P=0.0001), age tertiles (second and third tertiles, ORadj: 2.0 and 4.7, P=0.0001), Charlson Comorbidity Index (second and third tertiles, ORadj: 4.8 and 8.6, P=0.0001), heart failure, and previous and in-hospital antihypertensive treatment. Our data show that AS and admission systolic BP <120 mm Hg had independent prognostic value for all-cause mortality in patients with COVID-19 requiring hospitalization.

Development of a Multi-Criteria Design Optimization Methodology for Automotive Plastics Parts.

The plastic industry is undergoing drastic changes, due to the customer sustainability perception of plastics, and the eruption of new processes (such 3D printing) and materials (such as renewably sourced resins). To enable a fast transition to high-quality, sustainable plastic applications, a specific methodology could be a key competitive advantage. This novel methodology is focused on improving the objectivity and efficiency of plastic production and the design review process. It is applicable to discrete optimization events in any product lifecycle milestone, from concept design to serial production stages. The methodology includes a natural way to capture plastic-related knowledge and trends, oriented towards building a dynamic "interaction matrix", with a list of potential optimizations and their positive or negative impacts in a comprehensive set of multi-criteria evaluations. With an innovative approach, the matrix allows the possibility to incorporate a business strategy, which could be different at every lifecycle stage. The business strategy is translated from the common "verbal" definition into a quantitative set of "Target and Restrictions", making it possible to detect and prioritize the best potential design optimization changes according to the strategy. This methodology helps to model and compare design alternatives, verify impacts in every evaluation criteria, and make robust and objective information-based decisions. The application of the methodology in real cases of plastic material design optimization in the automotive industry has provided remarkable results, accelerating the detection of improvement methods aligned with the strategy and maximizing the improvement in product competitiveness and sustainability. In comparison with the simultaneous application of existing mono-criteria optimization methodologies (such as "Design to Cost" or "Eco Design") and subjective expert-based reviews, the novel methodology has a reduced workload and risks, confirming its potential for future application and further development in other polymer-based products, such as consumer goods or packaging.

Inverse design of an isotropic suspended Kirchhoff rod: theoretical and numerical results on the uniqueness of the natural shape.

Solving the equations for Kirchhoff elastic rods has been widely explored for decades in mathematics, physics and computer science, with significant applications in the modelling of thin flexible structures such as DNA, hair or climbing plants. As demonstrated in previous experimental and theoretical studies, the natural curvature plays an important role in the equilibrium shape of a Kirchhoff rod, even in the simple case where the rod is isotropic and suspended under gravity. In this paper, we investigate the reverse problem: can we characterize the natural curvature of a suspended isotropic rod, given an equilibrium curve? We prove that although there exists an infinite number of natural curvatures that are compatible with the prescribed equilibrium, they are all equivalent in the sense that they correspond to a unique natural shape for the rod. This natural shape can be computed efficiently by solving in sequence three linear initial value problems, starting from any framing of the input curve. We provide several numerical experiments to illustrate this uniqueness result, and finally discuss its potential impact on non-invasive parameter estimation and inverse design of thin elastic rods.

Gold nanostar synthesis with a silver seed mediated growth method.

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape. There is a great interest in using nano-colloids for photo-thermal ablation, drug delivery and many other biomedical applications. Gold is particularly used because of its low toxicity. A property of metal nano-colloids is that they can have a strong surface plasmon resonance. The peak of the surface plasmon resonance mode depends on the structure and composition of the metal nano-colloids. Since the surface plasmon resonance mode is stimulated with light there is a need to have the peak absorbance in the near infrared where biological tissue transmissivity is maximal. We present a method to synthesize star shaped colloidal gold, also known as star shaped nanoparticles or nanostars. This method is based on a solution containing silver seeds that are used as the nucleating agent for anisotropic growth of gold colloids. Scanning electron microscopy (SEM) analysis of the resulting gold colloid showed that 70 % of the nanostructures were nanostars. The other 30 % of the particles were amorphous clusters of decahedra and rhomboids. The absorbance peak of the nanostars was detected to be in the near infrared (840 nm). Thus, our method produces gold nanostars suitable for biomedical applications, particularly for photo-thermal ablation.

Conocimientos y actitudes acerca de las ITS y el VIH/SIDA de los adolescentes varones en dos comunidades zonales de Chimbote-Perú, 2010 / Knowledge and attitudes about STI and HIV/AIDS in teen boys in two communities of zonal Chimbote-Perú, 2010

Las ITS y el VIH/SIDA en Perú afectan principalmente a la población joven, de 15 a 24 años, sexualmente activa, y del sexo masculino; por lo tanto, es en este grupo de edad donde se tienen que desarrollar intervenciones enérgicas, orientadas hacia el cambio de conductas. La realización de investigaciones que monitoreen indicadores relacionados al conocimiento y las actitudes sexuales, como determinantes del comportamiento de riesgo en los jóvenes son fundamentales en al prevención de estas enfermedades. OBJETIVO: Describir el conocimiento y las actitudes sexuales acerca de las ITS y el VIH/SIDA que tienen los adolescentes varones de dos comunidades zonales de Chimbote-Perú en el año 2010. MATERIAL Y MÉTODOS: Investigación cuantitativa, de nivel descriptivo transversal, de ámbito comunitario. Se aplicó una encuesta voluntaria a 100 adolescentes varones de 10 a 19 años de edad con domicilio en el pueblo joven 2 de Junio y la urbanización Laderas del Norte, de Chimbote, durante los meses de abril y mayo de 2010. RESULTADOS: Edad media 15,2 años. La fuente de información citada con más frecuencia y la más importante fueron los medios de comunicación (52%). 28% de varones refieren relaciones sexuales con una edad media de iniciación sexual de 14,7 años, con un rango de 12 a 18 años, habiendo tenido el 64,3% su primera relación coital antes del primer año de relación. El 99% sabía dónde recurrir en situaciones de riesgo. El 75% de varones desconoce las dimensiones básicas sobre las ITS y el VIH/SIDA; y el 74% presenta actitudes desfavorables hacia estas enfermedades. CONCLUSIÓN: La mayoría de adolescentes varones no tiene los conocimientos suficientes sobre las ITS y VIH/SIDA, con actitudes desfavorables frente al tema.

Young people sexually active of male sex are mostly affected by STI and HIV/AIDS of 15 to 24 aged in Perú. Therefore, this group etareo demands intervention in order to change their sexual behaviour. Searches on monitoring indicadors related to knowledge and attitudes toward sex, the ones considered determinants in young people behaviour of risk, are fundamental in the prevention of these illnesses. OBJECTIVE: to describe the sexual knowledge and attitudes toward STI and HIV/AIDS of young people of male sex in two communities in Chimbote-Perú in 2010. METHODOLOGY: It is a quantitative, non experimental, descriptive and transversal study in the communitary field. A voluntary survey was applied to 100 and 19 years of age who lived in the locality of 2010. RESULTS: A verage age 15,2. The most important source of information on sexuality was the mass media (52%). 28% of adolescent males refe their sexual initiation with an age mean of 14,7, ranged from 12 to 18 years of age. 64,3% had their first sexual relation before the first year of sentimental relation. 75% of adolescent males do not know the basic dimensions of STI and HIV/AIDS: 74% present non favorable attitudes toward these illnesses. Conclusion: Most of adolescent males do not have enough knowledge about STI and HIV/AIDS, having non favorable attitudes toward it.

Preparation of phenanthrenes by photocyclization of stilbenes containing a tosyl group on the central double bond. A versatile approach to the synthesis of phenanthrenes and phenanthrenoids.

We have developed a useful modification of the classical preparation of phenanthrenes by UV irradiation of stilbenes in the presence of an oxidant. This modification involves the irradiation, in the presence of base, of stilbenes possessing a sulfonyl group linked to the central double bond. We have proved that this protocol can be successfully applied for the synthesis of diverse phenanthrenes and phenanthrenoids.

Optimización de la hidrólisis de arroz ñelen por Aspergillus niger para usarlo como sustrato en la obtención de etanol / Optimization of the hydrolysis of broken rice by Aspergillus niger for using as a substrate in ethanol obtaining

El presente trabajo de investigación tuvo como objetivo optimizar la hidrólisis de arroz ñelen por Aspergillus niger para usarlo como sustrato en la obtención de etanol. Para ello se construyeron 15 biorreactores de 21 cm de altura tipo tanque no agitado. La preparación del inóculo fue realizado a concentraciones de 10 elevado a 5, 10 elevado a 10 y 10 elevado a 7 esporas de A. niger/mL, realizando el conteo en cámara Neubauer. El medio de cultivo fue formulado a partir de diferentes concentraciones de arroz ñelen 200, 300 y 400g de arroz ñelen/L agua. El bioproceso se llevo a cabo a 45°C; a pH de 5,5 – 6,0 y durante un tiempo de 4,5 y 6 días. Se demostró que los parámetros óptimos para obtener 100 g de glucosa/L de hidrolizado a partir de arroz ñelen fueron a partir de una concentración de 400 g de ñelen/L de agua, 10 elevado a 5 esporas de A. niger/mL de engrudo y un tiempo de 6 días

This research work aimed to optimize the hydrolysis of broken rice by Aspergillus niger to use as substrate in the ethanol yield. This 15 bioreactors were constructed of 21 cm high, not stirred tank type. The preparation of the inoculums was performed at concentration of 10 raised to 5, 10 raised to 6 and 10 raised to 7 spores of A. niger/mL by counting in Neubauer chamber. The culture medium was made from different concentrations of broken rice 200, 300 and 400 g broken rice/L water. The bioprocess was carried out at 45 °C. At pH 5,5 – 6,0 and for a time of 4,5 and 6 days. It was shown that the optimal parameters to obtain 100 g glucose/L hydrolyzed from broken rice were from a concentration of 400 g broken rice/L water, 10 raised to 5 spores of A. niger/mL of paste and a time of 6 days.