Lignocellulosic biorefineries: A multiscale approach for resource exploitation.

Biomass can become the source for chemicals towards a sustainable production system. However, the challenges it presents such as the variety of species, their widespread and sparse availability, and the expensive transportation claims for an integrated approach to design the novel production system. Multiscale approaches have not been properly extended to biorefineryes design and deployment, due to the comprehensive experimental and modelling work they require. A systems perspective provides the systematic framework to analyze the availability and composition of raw materials across regions, how that affects process design, the portfolio of products that can be obtained by evaluating the strong link between the biomass features and the process design. The use of lignocellulosic materials requires for a multidisciplinary work, that must lead to new process engineers with technical competences in biology, biotechnology but also process engineering, mathematics, computer science and social sciences towards a sustainable process/chemical industry.

Integrated Renewable Production of Sorbitol and Xylitol from Switchgrass.

This work deals with the design of integrated facilities for the production of xylitol and sorbitol from lignocellulosic biomass. Xylitol can be obtained from xylose via fermentation or catalytic hydrogenation. Sorbitol is obtained from glucose, but preferably from fructose, and also via fermentation or catalytic hydrogenation. Fructose can be obtained from glucose via isomerization. Thus, a superstructure of alternatives is formulated to process switchgrass, corn stover, miscanthus, and other agricultural and forestry residues. Different pretreatments, such as dilute acid or ammonia fiber explosion (AFEX), for the fractionation of the biomass are evaluated. Next, after hydrolysis, the C5 and C6 sugars are processed separately for which a catalytic or a fermentation stage are considered. Glucose has to be isomerized before it can be processed. Finally, crystallization in a multistage evaporator system is used for purification. The optimization of the system is done by the use of dilute acid and the catalytic system. A system of 3 crystallizers is selected. For a facility that produces 145 kt/yr of xylitol and 157.6 kt/yr of sorbitol, the investment adds up to 120.74 M€ for a production cost of 0.28 €/kg products. The inverse engineering of biomass was also performed resulting in a composition of 15% water, 20% cellulose, 40% hemicellulose, 15% lignin, and 5% ash. The closest biomass corresponds to Sargassum (brown algae), which is capable of producing 230.5 kt/yr of xylitol and 116 kt/yr of sorbitol with investment and production costs of 120.5 M€ and 0.25 €/kg products, respectively.

Drospirenone: a Latin American perspective for oestrogen-free oral contraception.

AIM: Combined hormonal contraceptives, despite their high efficacy, are associated with an increased relative risk of cardiovascular events. The contraceptive mechanism of action of combined pills depends fundamentally on their progestin component. METHODS: A narrative review was performed. RESULTS: The drospirenone-only pill, including this synthetic progestogen with antimineralocorticoid and antiandrogenic activity, has high contraceptive efficacy that has been demonstrated with a 24-day schedule of 4-day administration of hormone-free pills. Due to its safety profile, the drospirenone-only pill is suitable even in high-risk populations, such as women with high blood pressure, thromboembolism, smoking or dyslipidemia. CONCLUSION: Considering the increasing prevalence of these comorbidities in Latin America, the 4 mg drospirenone-only pill is suggested as one of the strategies of choice in the region for those women who choose oral contraceptives.

Analysis and new contraception frontiers with combined vaginal rings.

Combined vaginal rings (ethinylestradiol (EE)/desogestrel), indicated for contraception, are highly effective, comparable to other combined hormonal contraceptives, such as pills. In addition to this benefit, vaginal rings are easy to use, with a probable lower risk of forgetting, due to their non-daily, monthly schedule. Besides, for users with poor gastric tolerance to oral formulations, they represent a method with safety and comparable extraconceptive benefits. The latest generation rings have a novel polymeric structure, do not need special storage methods and do not generate accelerated initial release of EE, reducing the early increased systemic exposure to the synthetic steroids they contain. This review describes main aspects related to its use, efficacy, and safety for contraceptive purposes.

Estudio PIENSA: efecto de la asesoría sobre la elección de anticonceptivos hormonales combinados en mujeres chilenas / PIENSA study: effect of advice on the choice of combined hormonal contraceptives in Chilean women

Objetivos: Evaluar la asesoría acerca de los anticonceptivos hormonales combinados de auto administración por parte de profesionales de la salud y cómo influye en el cambio o elección del método a utilizar. Método: Durante la consulta ginecológica habitual, se registra la elección del método anticonceptivo (MAC) combinado de auto administración (píldora, anillo o parche transdérmico) previa a la asesoría del médico y posterior a esta. El registro se realiza por medio de una encuesta que debe llenar la paciente y otra a completar por el médico. Resultados: Luego de la asesoría, de las 867 mujeres participantes un 11,6 por ciento variaron su opción de MAC elegido previamente. La píldora, originalmente el método más elegido, disminuyó en las preferencias, aunque continuó siéndolo y las otras opciones aumentaron. La píldora anticonceptiva bajó en un 13,4 por ciento desde su elección inicial, el anillo vaginal y el parche transdérmico incrementaron su elección en un 63,6 y 56,7 por ciento respectivamente. Conclusión: Las píldoras son el MAC hormonal combinado preferido por las mujeres participantes. Sin embargo entregándo una información estandarizada se produce un impacto en la elección anticonceptiva, favoreciendo los métodos menos tradicionales y de uso prolongado como son el anillo vaginal y parche transdérmico.

Objectives: To evaluate the impact of health care professional counseling in the choice of combined self-administered contraceptive method. It also assesses how such advice influences in the final contraceptive choice or how it changes from the original. Method: During routine gynecological consultation, the patient's self-administered contraceptive method (pill, vaginal ring and transdermal patch) preference was registered. This was done before and after physician counseling, through a survey filled by both the patient and the physician. Results: After counseling, of the 867 women who participated, 11.6 percent changed their previously chosen contraceptive. The pill, originally the chosen method of the majority of women, decreased in terms of preference; although the pill continued to be the preferred contraceptive method, preference for other methods increased. The contraceptive pill decreased 13.4 percent in the preference rating, while the choice of the vaginal ring and the transdermal patch increased by 63.65 and 56.7 percent respectively. Conclusion: The pill is women's preferred combined self-administered contraceptive method. Nevertheless during counseling, a standardized information impacts in the contraceptive choice increasing the preference of less conventional methods as transdermal patch and vaginal ring.

Estudio de laboratório y clínico con un nuevo progestageno combinado con etinil estradiol usado en anticoncepción / Laboratory and clinical study with a new progestogen combined with estradiol used in contraception

Se usó un anticonceptivo hormonal oral combinado que contiene etinil estradiol 0,03 mg y desogestrel 0,15 mg en 78 multíparas. Se analizaron clinicamente 705 ciclos de tratamiento. Se midieron con técnica de radioinmunoensayo los niveles de HDL-colesterol, LDL-colesterol, SHBG y testosterona libre plasmática en todas las mujeres al inicio del programa, 6 meses y 12 meses de uso del preparado. Se hace evidente un aumento de HDL-colesterol y SHBG y disminución del LDL-colesterol y testosterona libre. Se destaca la muy baja incidencia de efectos secundarios sobre las características del ciclo menstrual. El resto de los parámetros clínicos no difiere fundamentalmente de otros anticonceptivos hormonales combinados de baja dosis. Se discute la importancia de las variaciones de algunos parámetros bioquímicos inducidas por estrogénos y progestágenos en la génesis de enfermedad cardiovascular. Se concluye que las variaciones bioquímicas y hormonales inducidas probablemente por desogestrel serían beneficiosas, en el sentido de disminuir, por lo menos teóricamente, la incidencia de enfermedad cardiovascular