Optimal Pretreatment System of Flowback Water from Shale Gas Production

Shale gas has emerged as a potential resource to transform the global energy market. Nevertheless, gas extraction from tight shale formations is only possible after horizontal drilling and hydraulic fracturing, which generally demand large amounts of water. Part of the ejected fracturing fluid returns to the surface as flowback water, containing a variety of pollutants. For this reason, water reuse and water recycling technologies have received further interest for enhancing overall shale gas process efficiency and sustainability. Water pretreatment systems (WPSs) can play an important role for achieving this goal. This paper introduces a new optimization model for WPS simultaneous synthesis, especially developed for flowback water from shale gas production. A multistage superstructure is proposed for the optimal WPS design, including several water pretreatment alternatives. The mathematical model is formulated via generalized disjunctive programming (GDP) and solved by re-formulation as a mixed-integer nonlinear programming (MINLP) problem, to minimize the total annualized cost. Hence, the superstructure allows identifying the optimal pretreatment sequence with minimum cost, according to inlet water composition and wastewater-desired destination (i.e., water reuse as fracking fluid or recycling). Three case studies are performed to illustrate the applicability of the proposed approach under specific composition constraints. Thus, four distinct flowback water compositions are evaluated for the different target conditions. The results highlight the ability of the developed model for the cost-effective WPS synthesis, by reaching the required water compositions for each specified destination

Frecuencia de los sistemas ABO y RH en personas que acudieron al servicio académico asistencial de análisis clínicos

ABO and Rhesus blood group system were determined from 3655 patients attending The Assitentíal Service of Clinical Ana1ysis bclonging to Facultad de Farmacia y Bioquímica of Universidad Nacional Mayor de San Marcos in the period of time betwccn 2003 and 2005, the goal of this study was to estímate the frequency of blood group system ABO and Rh in the population under study and to compare our findings with other investigations. It was used specific anti serum; moreover, all test were conducted following conventional methodology. The statistic analysis of results provided the following frequencies: 73.36%0+, 0.38%0-, 18.85%A+, 0.27 A-, 5.85%B+ and 1.45%AB%+. The differences of frequencies of ABO and Rh blood system were related to the Peruvian geographic region to which patients carne from. Also, it was found slight differences when thc results obtained from this investigation were compared with previous studies.Se determinaron los grupos sanguíneos de los sistemas ABO y factor Rh en 3655 personas que acudieron al Servicio Académico Asistencial de Análisis Clínicos de la Facultad de Farmacia y Bioquímica de la Universidad Nacional Mayor de San Marcos, entre los años 2003-2005, con la intención de saber la frecuencia de los mismos, y conocer nuestras peculiaridades de tipos sanguíneos, además de comparar nuestras frecuencias con otras investigaciones. Se utilizó reactivos antisueros estandarizados siguiendo las técnicas convencionales. El análisis estadístico de los resultados en los grupos sanguíneos del sistema ABO y Factor Rh nos dio: "O" Positivo 73.36%, "O" Negativo 0.38%, "A". Positivo 18.85%, "A" negativo 0.27%, "B" Positivo 5.85% y" AB'' positivo 1.45%, estas frecuencias variaron según la región de procedencia de las personas involucradas (Costa, Sierra y Selva), así mismo se encontró ligeras variaciones al comparar con otros estudios que se realizaron en el transcurso de anteriores años

Evaluación semicuantitativa de glucógeno megacariocítico para el diagnóstico de púrpura trombocitopénica idiopática

The aim of this study was to determine semiquantitatively megakaryocyte glycogen and related parameters as an aid to diagnosis and treatment of idiopathic thrombocytopenic purpura (ITP). The tests were applied to 100 patients diagnosed with ITP from various hospitals and clinics, and 100 apparently healthy subjects who was gave informed consent according to the Declaration of Helsinki. Investigating the presence of glycogen in megakaryocytes of bone marrow smears using the method of peryodic acid-Schiff and complementary tests of hemostasis: platelets by the method of Rees-Ecker, mean platelet volume (MPV) using the automatic analyzer Sysmex XE-2100, prothrombin time, partial thromboplastin time (PTT), bleeding time, fibrinogen, hemoglobin and red blood cell count by the usual methods. We conclude that patients with ITP megakaryocyte glycogen had decreased (100%), alterations in some coagulation parameters such as increased bleeding time (98%), decreased number of platelets (100%) remaining prothrombin time, PTT and fibrinogen, and increased MPV (88%). In addition, we found a significant positive correlation between decreased levels of platelets and the MPV.El objetivo del presente estudio fue determinar semicuantitativamente glucógeno megacariocítico y los parámetros afines como ayuda al diagnóstico y tratamiento de la púrpura trombocitopénica idiopática (PTI). Las pruebas se aplicaron a 100 pacientes con diagnóstico de PTI provenientes de diversos hospitales y clínicas y en 100 sujetos aparentemente sanos, quienes dieron su consentimiento informado de acuerdo a la Declaración de Helsinki. Se investigó la presencia de glucógeno en los megacariocitos del frotis de médula ósea usando el método del ácido peryódico de Schiff y exámenes complementarios de la hemostasia: recuento de plaquetas por el método de Rees-Ecker, volumen plaquetario medio (VPM) utilizando el analizador automático Sysmex XE-2100, tiempo de protrombina, tiempo parcial de tromboplastina (TPT), tiempo de sangría, fibrinógeno, hemoglobina y recuento de glóbulos rojos por los métodos usuales. Se concluye que los pacientes con PTI presentaban disminución de glucógeno megacariocítico (100%); alteraciones en algunos de los parámetros de la coagulación como: aumento del tiempo de sangría (98%), disminución del número de plaquetas (100%); manteniéndose los tiempos de protrombina, TPT y fibrinógeno, y aumento en el VPM (88%). Además, se encontró una correlación positiva y significativa entre los valores disminuidos de plaquetas y el VPM

Perfil hepático en adultos aparentemente sanos nativos de altura, Junín, 4105 msnm

Biochemical tests were performed to assess the hepatic performance of 50 native subjects from highlands (Community Villa Junín, 4105 m) and a similar group from sea level (Lima, 150 m). In fasting state were determined albumin concentration and the performance of hepatic enzymes, GPT, GOT, ALP, GGT and LDH. Were found significant differences between these parameters; with major difference in albumin, GPT, LDH and lower for FA, comparing natives from highlands front to the ones from level of sea. We also found differences between enzymatic activities of GOT, GPT, LDH and FA according to gender, age and place of origin of the subjects at 95% confidence. Exists correlation between the values of GOT and GGT, and between GPT and GGT, for the native subjects from highlands. Likewise a correlation between GPT and FA, between GOT and GPT; and between albumin and GGT, for subjects from the level of the sea.Se realizaron pruebas bioquímicas para evaluar el estado hepático de 50 sujetos nativos de altura (Comunidad Villa Junín, 4105 m) y un grupo similar de personas nivel del mar (Lima, 150 m). En estado de ayuno se les determinó la concentración de albúmina y la actividad de las enzimas hepáticas: GPT, GOT, FA, GGT y LDH. Se encontró diferencias significativas entre éstos parámetros; siendo mayores en albúmina, GPT, LDH y menor en FA en los sujetos nativos de altura frente a los de nivel del mar. Asimismo se encontró diferencia entre las actividades enzimáticas de GOT, GPT, LDH y FA según el género, edad y lugar de procedencia de los sujetos de estudio al 95% de intervalo de confianza. Existe correlación entre los valores de GOT y GGT, y entre GPT y GGT, para los sujetos nativos de altura. Asimismo una correlación entre GPT y FA, entre GOT y GPT; y entre albúmina y GGT, para sujetos del nivel del mar

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease