Insights and strategies for improving equity in graduate school admissions.

Applying to graduate school can be particularly challenging for students from historically minoritized backgrounds due to a hidden curriculum in the graduate admissions process. To address this issue, a team of volunteer STEM trainees established the Científico Latino Graduate Student Mentorship Initiative (CL-GSMI) in 2019 to support applicants from historically minoritized backgrounds. CL-GSMI is designed to improve access to critical resources, including information, mentorship, and financial support, and has assisted 443 students in applying and matriculating to graduate school. Using program evaluation data from 2020 to 2021, we highlight areas in graduate school admissions that can be improved to promote equity and inclusion.

High-Affinity Binding of Chemokine Analogs that Display Ligand Bias at the HIV-1 Coreceptor CCR5.

The chemokine receptor CCR5 is a drug target to prevent transmission of HIV/AIDS. We studied four analogs of the native chemokine regulated, on activation, normal T-cell-expressed, and secreted (RANTES) (CCL5) that have anti-HIV potencies of around 25 pM, which is more than four orders of magnitude higher than that of RANTES itself. It has been hypothesized that the ultrahigh potency of the analogs is due to their ability to bind populations of receptors not accessible to native chemokines. To test this hypothesis, we developed a homogeneous dual-color fluorescence cross-correlation spectroscopy assay for saturation- and competition-binding experiments. The fluorescence cross-correlation spectroscopy assay has the advantage that it does not rely on competition with radioactively labeled native chemokines used in conventional assays. We prepared site-specifically labeled fluorescent analogs using native chemical ligation of synthetic peptides, followed by bioorthogonal fluorescent labeling. We engineered a mammalian cell expression construct to provide fluorescently labeled CCR5, which was purified using a tandem immunoaffinity and size-exclusion chromatography approach to obtain monomeric fluorescent CCR5 in detergent solution. We found subnanomolar binding affinities for the two analogs 5P12-RANTES and 5P14-RANTES and about 20-fold reduced affinities for PSC-RANTES and 6P4-RANTES. Using homologous and heterologous competition experiments with unlabeled chemokine analogs, we conclude that the analogs all bind at the same binding site, whereas the native chemokines (RANTES and MIP-1α) fail to displace bound fluorescent analogs even at tens of micromolar concentrations. Our results can be rationalized with de novo structural models of the N-terminal tails of the synthetic chemokines that adopt a different binding mode as compared to the parent compound.

Ultrasound Surveillance in Endovascular Revascularization of Lower Limbs.

BACKGROUND: Endovascular surgery has become the initial treatment for most patients with chronic ischemia of the lower limbs. Few studies support ultrasound surveillance (US) of this kind of procedures. The purpose of this study was to evaluate the initial efficacy of duplex ultrasound as a surveillance method in endovascular treatment in symptomatic peripheral arterial disease patients in our center. MATERIAL AND METHODS: A total of 113 endovascular procedures performed in 106 patients between February 2013 and June 2015 were included. Follow-up included clinical assessment, physical examination, ankle-brachial index (ABI), plethysmography, and ultrasound at 1, 3, 6, 12, 18, and 24 months after surgery. Patients without a minimum follow-up of two controls were excluded. Worsening was defined as follows: (1) in ultrasound, a restenosis >70%; (2) from ABI, a decrease >0.15; (3) clinically, a decrease in claudication distance, reappearance rest pain, or worsening injuries; (4) in plethysmography, flattening in the curve. RESULTS: The average age was 68.3 years, with 72% being men. Twenty-two percent of treated lesions were iliac, 57% were femoropopliteal, and 21% were distal. There were 329 visits, with a mean follow-up of 13.5 months (3-31). The US detected permeability or moderate stenosis in 66 patients (58.4%) and restenosis or occlusion in 47 (41.6%). When compared with clinical status, there was a noncorrelation in 23% and a discrepancy with respect to the ABI of 27% and of 39% with plethysmography. All these differences were statistically significant (P < 0.001). Twenty-one reinterventions were performed (18.6%), six patients died (5.3%), and 11 required major amputation (9.7%). CONCLUSIONS: Clinical status and hemodynamics can detect restenosis or occlusion of the procedure in a large part of the cases, but it can omit more than 20% of these that were only detected by US. The ultrasound follow-up is of great help to increase the reliability of the control in patients with endovascular revascularization of lower limbs.

Contrast-Induced Nephropathy: A Fact or Fiction in Lower Limb Revascularization?

INTRODUCTION: Contrast-induced nephropathy (CIN) is defined as an increase >25% of serum creatinine from baseline, occurring in 24-48 hours after exposure to contrast, while alternative explanations for renal impairment have been excluded. The volume administered directly relates to risk, increasing by 12% per 100 mL of contrast. According to the series, its incidence varies between 3.3% and 8% in patients without renal damage and 12-50% in patients with chronic kidney disease (CKD) and/or diabetes mellitus (DM). The purpose of this study is to determine the incidence of CIN in endovascular revascularization of lower limbs in our center, where we apply the ALARA concept (As Low As Reasonably Achievable) to the use of contrast. MATERIAL AND METHODS: 163 patients who underwent endovascular revascularization procedures in lower limbs were included in this prospective observational study between February 2013 and April 2015. They were classified according to clinical stage and presence of DM and/or CKD. Data included serum creatinine values preoperative and postoperative, type and volume of contrast used. Patients on hemodialysis and those without sufficient analytical data were excluded. Chi-squared test and Student t-test were used for data analysis. P < 0.05 was considered statistically significant. RESULTS: 109 patients were enrolled, with 67% of DM and 31.5% of CKD. CIN incidence was 3.7% in patients without DM neither CKD, in DM was 6.8% and 12.5% in CKD. Mean creatinine presurgery was 97.96 and postsurgery 97.07, finding no significant differences between them (P = 0.753). Medium-contrast volume was 37.43 mL ± 22.3. The worsening variable (creatinine postsurgery minus creatinine presurgery) was evaluated according to clinical stage, DM, or CKD, being not significant in either group. CONCLUSIONS: In our experience, the dose administered of contrast was not related to the existence of postprocedure CIN, due to the policy of optimizing the use of contrast.

Influence of surface position along the working range of conoscopic holography sensors on dimensional verification of AISI 316 wire EDM machined surfaces.

Conoscopic holography (CH) is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F) and power (P) until the quality indicators Signal-to-Noise Ratio (SNR) and signal envelope (Total) meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR). Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP) on a CMM.

Routinely ultrasound surveillance improves outcome after endovascular treatment of peripheral arterial disease: propensity-matched comparisons of clinical outcomes after ultrasound or clinical-hemodynamic based surveillance programs.

BACKGROUND: Endovascular treatment (EVT) has replaced open repair as the first option in intermittent claudication (IC) and chronic limb-threatening ischemia (CLTI) in several centers. However, evidence of the most optimal post-procedural surveillance strategy is sparse. This study aimed to compare two routine surveillance programs after EVT of IC/CLTI: clinical and hemodynamic assessment (CHA) vs. duplex ultrasound (DUS) and clinical/hemodynamic assessment in combination. METHODS: Between February 2012 and December 2015, all patients with EVT of IC/CLTI were allocated to either CHA or DUS-based routine surveillance programs. The allocation-ratio was 1:2 (CHA:DUS), and propensity score matching (PSM) was used to control baseline differences between the groups. Follow-up visits in the CHA group consisted of clinical assessment and ABI at 3, 6, 12 and 24 months. Follow-up visits in DUS group consisted of clinical assessment, ABI, and target vessel DUS at 1, 3, 6, 12, 18 and 24 months. RESULTS: In total, 340 legs in 305 patients suffering from IC/CLTI were included; 111 (33%) in the CHA-group and 229 (67%) in the DUS group. The two groups were identical except for a significantly lower incidence of diabetes mellitus in the CHA group than the DUS group, 55% vs. 72%, respectively (P=006). Based on PSM, the CHA-group vs. the DUS-group was burdened of an increased risk of amputation (12.5% vs. 8.27%, HR=0.41 [95% CI: 0.17-0.96]), and a higher mortality (21.2% vs. 12.8%, HR=0.37 [95% CI: 0.19-0.72]). The reported differences in reintervention rate (7.5% vs. 12.8%, HR=1.12 [95% CI: 0.44-2.84]) were insignificant. The mean follow-up was 317 days (SD=0.214) in the CHA group and 611 days (SD=0.298) in the DUS group. CONCLUSIONS: Our results suggest that DUS-based routine surveillance after EVT of IC/CLTI is superior to CHA-based routine surveillance in improved amputation rate and mortality.

Usefulness of ultrasound-guided tibio-pedal access in patients with critical limb ischemia.

INTRODUCTION: Retrograde access performed guided by fluoroscopy or ultrasound. We aimed to analyze the usefulness of ultrasound in retrograde access in patients with critical limb ischemia. METHODS: Observational analytical study. From December 2013 to June 2019. We included all retrograde accesses that were guided by ultrasound. Our register assesses demographic and clinical data, the vessel used as retrograde access, the procedure performed, the amount of contrast agent used and time of fluoroscopy, access failure, and local complications. RESULTS: On 715 procedures performed, was used ultrasound-guided retrograde access in 25 patients (64% men). The mean age was 74.8 years (45-90), with 92% of diabetics and 32% of chronic renal failure. Two patients with Rutherford stage 4 and 23 with stage 5-6. In 24 (96%) patients the ultrasound-guided puncture was successful, while in one (4%) of them, it was not possible to enter the target vessel. After the punch, was achieved the technical success of revascularization in 19 (79.2%) patients, with 5 (20.8%) in whom did not the arterial injury was not overcome. The arteries used as retrograde access were: anterior tibial 11, posterior tibial 10, and peroneal in 4. The mean of contrast used was 63 mL (9-100 mL) with an average time of 43 min (15-76 min). Complications related did not observe in retrograde access. CONCLUSIONS: Ultrasound-guided retrograde distal access is an effective method that may use as a bailout method in those endovascular procedures in which it is not possible to cross the lesion anterogradely.

Usefulness of ultrasound-guided tibio-pedal access in patients with critical limb ischemia. / Utilidad de la ecografía en la punción retrógrada distal en la isquemia crítica de extremidades inferiores.

INTRODUCTION: Retrograde access performed guided by fluoroscopy or ultrasound. We aimed to analyze the usefulness of ultrasound in retrograde access in patients with critical limb ischemia. METHODS: Observational analytical study. From December 2013 to June 2019. We included all retrograde accesses that were guided by ultrasound. Our register assesses demographic and clinical data, the vessel used as retrograde access, the procedure performed, the amount of contrast agent used and time of fluoroscopy, access failure, and local complications. RESULTS: On 715 procedures performed, was used ultrasound-guided retrograde access in 25 patients (64% men). The mean age was 74.8 years (45-90), with 92% of diabetics and 32% of chronic renal failure. Two patients with Rutherford stage 4 and 23 with stage 5-6. In 24 (96%) patients the ultrasound-guided puncture was successful, while in one (4%) of them, it was not possible to enter the target vessel. After the punch, was achieved the technical success of revascularization in 19 (79.2%) patients, with 5(20.8%) in whom did not the arterial injury was not overcome. The arteries used as retrograde access were: anterior tibial 11, posterior tibial 10, and peroneal in 4. The mean of contrast used was 63 mL (9-100 ml) with an average time of 43 minutes (15- 76 min). Complications related did not observe in retrograde access. CONCLUSIONS: Ultrasound- guided retrograde distal access is an effective method that may use as a bailout method in those endovascular procedures in which it is not possible to cross the lesion anterogradely.

Role of an age-adjusted D-dimer cutoff level in the diagnosis algorithm of lower limb deep venous thrombosis in outpatients.

OBJECTIVE: Our goal was to analyze the utility of the age-adjusted D-dimer cutoff value in patients with clinically suspected deep venous thrombosis (DVT) in an ambulatory care setting, including distal DVTs. METHODS: This was an observational cohort study of 606 outpatients older than 18 years presenting with low or moderate clinical suspicion of lower limb DVT (measured by Wells scale). D-dimer levels were obtained, and duplex ultrasound was performed (including femoropopliteal and below-knee veins). We calculated sensitivity, specificity, and positive and negative predictive D-dimer values and when to apply the age-adjusted D-dimer cutoff value (D-dimer threshold = age × 10 µg/L). We split patients older than 50 years into 10-year age groups. We constructed receiver operating characteristic curves of the D-dimer test for each group to find the best threshold (defined as the value of D-dimer that gives more specificity, maintaining the maximum possible sensitivity). RESULTS: There were 249 men and 357 women with a mean age of 69.3 years; 41 patients were diagnosed with DVT. At a D-dimer threshold of 250 µg/L, sensitivity was 93%, specificity was 8%, positive predictive value was 7%, and negative predictive value was 94%. When the age-adjusted cutoff level was applied, global sensitivity was 76% and specificity 61%; positive predictive value was 12%, and negative predictive value was 97%. False-negative rate was 24%. We split patients older than 50 years into 10-year age groups: 50 to 60 years, 60 to 70 years, 70 to 80 years, and >80 years. The optimum thresholds were, respectively, 526 µg/L, 442.5 µg/L, 475 µg/L, and 549. µg/L. CONCLUSIONS: In our series, the age-adjusted D-dimer cutoff level is not useful in the diagnostic algorithm of DVT.

Biogas production from the liquid waste of distilled gin production: Optimization of UASB reactor performance with increasing organic loading rate for co-digestion with swine wastewater.

This study is the first test that proves high rate anaerobic digestion as an efficient technological process for the treatment of gin spent wash. The gin spent wash was co-digested in UASB reactors with swine wastewater, which provided nutrients and alkalinity. The process was optimized by increasing the proportion of gin spent wash in the feed, and thus the organic loading rate (OLR) up to reactor failure. Stable high- efficiency operation was reached at an OLR as high as 28.5 kg COD m-3 d-1, yielding 8.4 m3 CH4 m-3 d-1 and attaining a COD removal of 97.0%. At an organic loading rate of 32.0 kg COD m-3 d-1, the process became unstable and the reactor underwent over-acidification that drastically lowered the pH and suppressed methanogenesis. The failure of the reactor was caused by a combination of an organic overloading and alkalinity deficit that uncoupled acidogenesis and methanogenesis.

FAMILY LIFE STORIES AMONG TEENAGE MOTHERS: QUALITATIVE STUDY CONDUCTED AT HOSPITAL ENGATIVÁ ESE IN BOGOTÁ, COLOMBIA.

OBJECTIVE: To get an insight into the structure and dynamics of the original families of five teenage mothers through their life stories and their own experiences. METHODS: Qualitative study with a narrative approach based on the life stories of five teenage mothers delivered at Engativá Hospital. Semistructured interviews were used to gain insight into the organization and structure of their original families. Emerging categories were identified by means of text hermeneutics, and results were validated using triangulation across researchers. RESULTS: The nuclear families of the pregnant women interviewed were characterized by the inability to deal with conflict appropriately, separations, structuring of new homes, confusion regarding roles, and matriarchal authority; reconstituted homes where the girls lived their own lives on the edge, where little value was attached to education, and where sexual and affective education were ambiguous and contradictory; families with expulsive dynamics where the teenage mother found herself having to survive on her own. CONCLUSIONS: Our pregnant adolescents live in the midst of families with unfavorable structure and dynamics that prevent the nuclear family from responding appropriately to teenage pregnancy. Consequently, pregnancy is an unplanned and rarely desired outcome, and a situation in which the family just normalizes the pregnancy when it occurs. In this context, pregnant adolescents are the result of a chain of inequities, where schooling is not valued and competencies for coping with life cannot grow fully to become an input for development. The noticeable resilience of one of the participants points to the need to undertake new studies focusing on identifying those traits of the individual, the family and the couple that increase their ability to adapt to the new situation.

TITULO: HISTORIAS DE VIDA FAMILIAR EN MADRES ADOLESCENTES: ESTUDIO CUALITATIVO REALIZADO EN EL HOSPITAL ENGATIVÁ ESE EN BOGOTÁ, COLOMBIA. OBJETIVO: Indagar en los relatos personales de cinco madres adolescentes inmersas en sus historias de vida y la vivencia de estas. METODOS: Estudio de tipo cualitativo con enfoque narrativo, mediante historias de vida de cinco mujeres adolescentes a quienes se les atendió su parto en el Hospital Engativá; mediante entrevistas semiestructuradas se indagó sobre la organización y la dinámica familiar de sus familias de origen. Mediante la hermenéutica del texto se identificaron categorías emergentes y se validaron los resultados por medio de triangulación de investigadores. RESULTADOS: Los núcleos familiares de las mujeres gestantes entrevistadas se caracterizaron por el mal manejo del conflicto, por las separaciones, por la estructuración de nuevos hogares y por la confusión en el ejercicio de roles, con una autoridad de tipo matriarcal; hogares reconstituidos donde las adolescentes orbitaban para hacer sus vidas; donde se daba un menor valor a la escolarización y en los que la educación de la sexualidad y la afectividad fueron ambiguas y contradictorias; familias con dinámicas expulsivas donde la madre adolescente debió enfrentarse al mundo de la supervivencia. CONCLUSIONES: Las adolescentes embarazadas del estudio desarrollan su vida en familias con una estructura y una dinámica poco propicia, que no les permite reaccionar adecuadamente a la adolescencia. De esta manera, el embarazo es una resultante no planeada y pocas veces deseada, situación en la que la familia se limita a normalizarlo cuando este se presenta. En este contexto, las adolescentes gestantes son el resultado de una serie de inequidades, donde la escolaridad tiene un menor valor y el desarrollo de competencias para la vida no alcanza a completarse como insumo para el desarrollo. Se destaca la capacidad resiliente de una de las participantes, lo que invita a nuevos estudios que permitan identificar aquellos elementos personales, de la familia y de la pareja que incrementen la capacidad de adaptación a esta nueva situación.

G protein subtype-specific signaling bias in a series of CCR5 chemokine analogs.

Chemokines and some chemical analogs of chemokines prevent cellular HIV-1 entry when bound to the HIV-1 coreceptors C-C chemokine receptor 5 (CCR5) or C-X-C chemokine receptor 4 (CXCR4), which are G protein-coupled receptors (GPCRs). The ideal HIV-1 entry blocker targeting the coreceptors would display ligand bias and avoid activating G protein-mediated pathways that lead to inflammation. We compared CCR5-dependent activation of second messenger pathways in a single cell line. We studied two endogenous chemokines [RANTES (also known as CCL5) and MIP-1α (also known as CCL3)] and four chemokine analogs of RANTES (5P12-, 5P14-, 6P4-, and PSC-RANTES). We found that CCR5 signaled through both Gi/o and Gq/11 IP1 accumulation and Ca2+ flux arose from Gq/11 activation, rather than from Gßγ subunit release after Gi/o activation as had been previously proposed. The 6P4- and PSC-RANTES analogs were superagonists for Gq/11 activation, whereas the 5P12- and 5P14-RANTES analogs displayed a signaling bias for Gi/o These results demonstrate that RANTES analogs elicit G protein subtype-specific signaling bias and can cause CCR5 to couple preferentially to Gq/11 rather than to Gi/o signaling pathways. We propose that G protein subtype-specific signaling bias may be a general feature of GPCRs that can couple to more than one G protein family.

Guía para el estudio no invasivo de la isquemia crónica de los miembros inferiores / Guide for the non-invasive study of lower extremity chronic ischemia

Nuevamente, desde el Capítulo de Diagnóstico Vascular de la Sociedad Española de Angiología y Cirugía Vascularnos proponemos la actualización de una guía de diagnóstico. Concretamente, la Guía de estudio de la isquemiade miembros inferiores. Creemos que la elaboración, la difusión y la utilización de guías de todo tipo permitiráuna mayor homogenización en el uso y en la difusión de las técnicas de diagnóstico que utilizamos en nuestroquehacer diario. La homogenización permitirá una mayor fiabilidad y prestigio en estas exploraciones. Por otra parte, la naturaleza de las guías de diagnóstico requiere mucha menos renovación que otro tipo de guíasy de documentos: las exploraciones que configuran nuestro motivo de ser no suelen variar de forma profundaa lo largo del tiempo. Ahora bien, es cierto que las explicaciones pueden darse de otro modo y complementarlas ya existentes, en absoluto obsoletas. Con este espíritu hemos abordado la elaboración de esta actualización. Se ha respetado completamente la guía previa publicada en 2009. Solo nos hemos permitido reescribir, por suimportancia y por su papel como piedra angular en el estudio de la isquemia de miembros inferiores, el capítulodedicado al estudio con ecografía Doppler arterial de las extremidades inferiores, aunque siempre con una visióncomplementaria, no excluyente, a lo ya publicado hace tantos años. El resto de la guía expone tres exploracio-nes emergentes, no tratadas previamente, pues casi no existían, que pueden suponer un avance, una mejora sicabe, en el estudio arterial de las extremidades isquémicas. Se trata del tiempo de aceleración pedal, tema derabiosa actualidad, de la determinación de la presión transcutánea de oxígeno, tan importante en la patologíaisquémica del diabético, y, finalmente, de la angiografía de perfusión, técnica de diagnóstico emergente y coninfinidad de posibilidades, muchas de ellas ni siquiera estudiadas...(AU)

Once again, from the Vascular Diagnosis Chapter of the Spanish Society of Angiology and Vascular Surgery, wepropose to update a diagnostic guide. Specifically, the Lower Limb Ischemia Study Guide. We believe that theelaboration, diffusion, and use of guides of all kinds will allow a greater homogenization in the use and diffusion ofthe diagnostic techniques that we use in our daily work. Homogenization will allow greater reliability and prestigein these explorations. On the other hand, the nature of diagnostic guides requires much less renewal than other types of guides anddocuments: the examinations that make up our reason for being do not usually vary profoundly over time. Now, it istrue that the explanations can be given in another way and complement the existing ones, which are by no meansobsolete. It is in this spirit that we have approached the making of this update. The previous guideline publishedin 2009 has been fully respected. Due to its importance and its role as a cornerstone in the study of lower limbischemia, we have rewritten the chapter dedicated to the study with arterial Doppler ultrasound of the lower limbs,although always with a complementary vision, not exclusive, to what was already published so many years ago. The rest of the guide exposes three emerging explorations, not previously treated, since they hardly existed, whichmay represent an advance, an improvement, if possible, in the arterial study of ischemic extremities. It deals withpedal acceleration time, a high topic, with the determination of transcutaneous oxygen pressure, so important inthe ischemic pathology of diabetics, and, finally, with perfusion angiography, an emerging diagnostic techniquewith infinite possibilities, many of them not even studied. To carry out this work we have turned to proven professionals in each treated section. We believe that the guidewill help to better carry out our daily explorations in ischemia of the lower limbs.(AU)

Evaluation of different types of anaerobic seed sludge for the high rate anaerobic digestion of pig slurry in UASB reactors.

Three different types of anaerobic sludge (granular, thickened digestate and anaerobic sewage) were evaluated as seed inoculum sources for the high rate anaerobic digestion of pig slurry in UASB reactors. Granular sludge performance was optimal, allowing a high efficiency process yielding a volumetric methane production rate of 4.1LCH4L-1d-1 at 1.5days HRT (0.248LCH4g-1COD) at an organic loading rate of 16.4gCODL-1d-1. The thickened digestate sludge experimented flotation problems, thus resulting inappropriate for the UASB process. The anaerobic sewage sludge reactor experimented biomass wash-out, but allowed high process efficiency operation at 3days HRT, yielding a volumetric methane production rate of 1.7LCH4L-1d-1 (0.236LCH4g-1COD) at an organic loading rate of 7.2gCODL-1d-1. To guarantee the success of the UASB process, the settleable solids of the slurry must be previously removed.

Influence of headspace pressure on methane production in Biochemical Methane Potential (BMP) tests.

The biochemical methane potential test is the most commonly applied method to determine methane production from organic wastes. One of the parameters measured is the volume of biogas produced which can be determined manometrically by keeping the volume constant and measuring increases in pressure. In the present study, the effect of pressure accumulation in the headspace of the reactors has been studied. Triplicate batch trials employing cocoa shell, waste coffee grounds and dairy manure as substrates have been performed under two headspace pressure conditions. The results obtained in the study showed that headspace overpressures higher than 600mbar affected methane production for waste coffee grounds. On the contrary, headspace overpressures within a range of 600-1000mbar did not affect methane production for cocoa shell and dairy manure. With the analyses performed in the present work it has not been possible to determine the reasons for the lower methane yield value obtained for the waste coffee grounds under high headspace pressures.

Comparación entre amputaciones menores primarias respecto a amputaciones menores con revascularización previa en patología del pie diabético / Comparison between primary minor amputations and minor amputations with previous revascularization in diabetic foot pathology

INTRODUCCIÓN: la realización de amputaciones menores primarias en pacientes diabéticos es una práctica aún frecuente en servicios de cirugía vascular. El objetivo de este estudio es comparar la evolución de las amputaciones menores primarias respecto a las realizadas con revascularización previa, considerando la presencia o no de angiosoma directo que revascularice la zona del muñón que vamos a crear. MATERIAL Y MÉTODOS: se realizó un estudio observacional y comparativo sobre la población de pacientes diabéticos que requerían amputaciones menores de miembros inferiores ingresados en nuestro servicio durante el periodo comprendido entre enero y diciembre de 2018. La revascularización previa (o no) a la amputación menor se decidía con base en estudios hemodinámicos y posibilidades según pruebas de imagen. La muestra se dividió en cuatro grupos tomando en cuenta la necesidad-posibilidad de revascularización previa a la amputación menor y la presencia de vascularización basada en angiosoma directo o indirecto a la zona del muñón que íbamos a crear. Se valoró en cada grupo la tasa de amputaciones mayores, la tasa de curación de las amputaciones menores y la mortalidad. Consideramos significativa p < 0,05. RESULTADOS: se reclutaron 106 pacientes de enero a diciembre de 2018. Las tasas de curación de los muñones de amputación en los cuatro grupos no presentaron diferencias estadísticamente significativas (p = 0,085). Los pacientes no revascularizados mostraron una tasa de pérdida de extremidad más alta que el grupo previamente revascularizado, con una diferencia estadísticamente significativa entre los grupos (p = 0,002). CONCLUSIONES: la tasa de pérdida de extremidad es mayor en los pacientes que no son sometidos a cirugía de revascularización previa a la amputación menor, así como en los pacientes cuya vascularización depende de angiosomas indirectos al muñón creado

INTRODUCTION: the performance of primary minor amputations in diabetic patients is a frequent practice in vascular surgery services. The aim of this study is to compare the evolution of minor primary amputations, with those performed with previous revascularization, considering the presence or not of a direct angiosome that revascularizes the stump area that we are going to create. MATERIAL AND METHODS: an observational and comparative study was performed on diabetic patients who required minor lower limb amputations admitted to our department during the period from January to December 2018. The revascularization prior, or not, to minor amputation, was decided based on hemodynamic studies and possibilities according to imaging tests. Patients were divided into 4 groups considering the need-possibility of revascularization prior to minor amputation, and vascularization based on direct or indirect angiosome to the area of the stump that we were going to create. The rate of major amputations, the healing rate of minor amputations, and mortality were assessed in each group. We consider significant p < 0.05. RESULTS: 106 patients were recruited, from January to December 2018. The healing rate of the amputation stumps in the four groups did not show statistically significant differences (p = 0.085). Non-revascularized patients showed a higher rate of limb loss respect the previously revascularized group, with a statistically significant difference between the groups (p = 0.002). CONCLUSIONS: the rate of limb loss is higher in patients who do not undergo revascularization surgery prior to minor amputation, as well as in patients whose vascularization depends on indirect angiosomes to the created stump

Anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure in a single continuously stirred tank reactor process: Limits in co-substrate ratios and organic loading rate.

Mesophilic anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure was investigated with the aim of determining the treatment limits in terms of the cheese whey fraction in feed and the organic loading rate. The results of a continuous stirred tank reactor that was operated with a hydraulic retention time of 15.6 days showed that the co-digestion process was possible with a cheese whey fraction as high as 85% in the feed. The efficiency of the process was similar within the range of the 15-85% cheese whey fraction. To study the effect of the increasing loading rate, the HRT was progressively shortened with the 65% cheese whey fraction in the feed. The reactor efficiency dropped as the HRT decreased but enabled a stable operation over 8.7 days of HRT. At these operating conditions, a volumetric methane production rate of 1.37 m(3) CH4 m(-3) d(-1) was achieved.

Role of contrast-enhanced ultrasound arterial mapping in surgical planning for patients with critical limb ischemia.

The goal of the study described here was to evaluate the role of contrast-enhanced ultrasound (CEUS) arterial mapping in surgical planning in cases of critical limb ischemia. From March 2007 to December 2012, 565 consecutive patients with critical limb ischemia of the lower limbs were treated and initially examined with only ultrasound (US) arterial mapping. For 479 of the 565 patients, basic US examination results were deemed sufficient for surgical planning (group A). That is, US examination provided sufficient information to decide a surgical plan to treat those patients. In the remaining 86 patients, basic US examination was insufficient for revascularization planning, and CEUS examination was performed (group B). In 5 cases, CEUS results were also insufficient for surgical planning, as a suitable outflow vessel was not visualized. In these cases, a pre-operative arteriogram was performed. To assess the usefulness of CEUS, we compared results of examinations with and without contrast administration, surgical findings and angiographic findings when available. Data were collected prospectively. Examinations were compared by establishing the degree of agreement between results of paired examinations and degree of agreement between CEUS results and surgical findings. Clinical, hemodynamic (ankle-brachial index) and duplex follow-up was performed at 1 and 3 mo to evaluate cumulative patency of the procedures in each group. Within group B, degree of agreement between basic US and CEUS was 46.5%. CEUS resulted in a change in the surgical plan in 46 of 86 patients. Among all 565 patients, degree of agreement between surgical decision based on basic ultrasound arterial mapping and final decision based on surgical findings was 87.1%, and improved to 95.2% with CEUS (p = 0.00001, κ index = 0.823). Degree of agreement between the ultrasound-based decision and surgical findings was 97.5% in group A (κ index = 0.818) and 94.2% in group B (κ = 0.848). There was no significant difference between groups (p = 0.784). Within group B, of the five arteriograms performed, results of only one matched well the US mapping findings. Vessel patency at 1 and 3 mo did not significantly differ between patients whose surgical planning was based on basic US and patients whose planning was based on CEUS (p = 0.418 and p = 0.489, respectively). US arterial mapping is an excellent tool for surgical planning in critical limb ischemia. CEUS arterial mapping improves the accuracy of ultrasound examination in patients with critical limb ischemia, especially in patients with inconclusive non-enhanced exams.