Production and optimization of biodiesel using mixed immobilized biocatalysts in packed bed reactor.

Vegetable oils are used as raw materials for biodiesel production using transesterification reaction. Several methods for the production of biodiesel were developed using chemical (alkali and acidic compounds) and biological catalysts (lipases). Biodiesel production catalyzed by lipases is energy and cost-saving processes and is carried out at normal temperature and pressure. The need for an efficient method for screening larger number of variables has led to the adoption of statistical experimental design. In the present study, packed bed reactor was designed to study with mixed immobilized biocatalysts to have higher productivity under optimum conditions. Contrary to the single-step acyl migration mechanism, a two-step stepwise reaction mechanism involving immobilized Candida rugosa lipase and immobilized Rhizopus oryzae cells was employed for the present work. This method was chosen because enzymatic hydrolysis followed by esterification can tolerate high free fatty acid containing oils. The effects of flow rate and bed height on biodiesel yield were studied using two factors five-level central composite design (CCD) and response surface methodology (RSM). Maximum biodiesel yield of 85 and 81 % was obtained for jatropha oil and karanja oil with the optimum bed height and optimum flow rate of 32.6 cm and 1.35 L/h, and 32.6 cm and 1.36 L/h, respectively.

Heterogeneous distribution of serum prolactin values in apparently healthy young women, and the effects of oral contraceptive medication.

Controversy over effects of oral contraceptives (OCs) on serum prolactin (PRL) levels from retrospective studies suggested performing a prospective study. Statistical analyses of PRL levels in 552 reproductive-age, nonmedicated women indicated a provisionally lognormal distribution of values less than 15 ng/ml, contaminated by a small number of abnormally high values less than or equal to 90 mg/ml. Truncated samples were used to estimate a "normal range" of PRL levels for three subsets of the study sample, classified according to number of weeks after pregnancy. Fifty-microgram estrogen-containing OCs doubled basal PRL levels at 5 to 8 weeks in those whose initial control values fell below 15 ng/ml, but the PRL elevation was no longer evident at 6 months of drug use. These OCs induced a small but significant lowering of PRL at 5 to 8 weeks in those with control levels of 15 ng/ml or higher. Thirty-five-microgram estrogen-containing OCs failed to alter PRL levels at 5 to 8 weeks in those with control values less than 15 ng/ml.

Choosing the appropriate oral contraceptive.

PIP: The estrogen and progestin in most oral contraceptives, regardless of amounts, can produce undesirable side effects in any woman. The convenience and effectiveness, however, make oral contraceptives an excellent birth control method for the correctly screened patient. The use of relatively small doses of estrogen combined with a progestin complementary to the estrogenic, progestogenic, and androgenic needs of the patient will reduce the risk of side effects. Above the 50 ug estrogen level there is significantly higher risk of pulmonary embolism, venous thrombosis, and cerebral thrombosis. Hypertension, depression and hepatic disorders are other potential side effects. Less serious complications are breakthrough bleeding, likely caused by low level estrogen dosage and amenorrhea. Progestogenic effects include sustained noncyclic weight gain and amenorrhea. Prescribing these agents necessitates adequate follow-up and willingness to alter the prescription.^ieng

Galactorrhea associated with primary hypothyroidism. Report of two cases.

Two patients with primary hypothyroidism and galactorrhea are described. Elevated serum prolactin and thyroid-stimulating hormone levels were present. Following adequate thyroid hormone replacement restoration of clinical euthyroidism and cessation of galactorrhea occurred with a fall of both TSH and prolactin levels to normal.

Purification and characterization of a sperm-coating antigen from human seminal plasma.

A sperm-coating antigen has been purified from human seminal plasma by a combination of fractionation methods including ammonium sulfate precipitation, Sephadex G-100 gel filtration, and diethylaminoethyl cellulose ion-exchange chromatography. The purified antigen was demonstrated to be immunologically identical sperm-coating antigen, not derived from blood serum but having immunologically cross-relating antigens in milk and saliva, and a glycoprotein with a molecular weight of approximately 33,000. The purpose of purifying this antigen was discussed.

Treatment of urinary stress incontinence. Use of dermal graft in the sling procedure.

Use of dermal graft for a urethral sling in treating urinary stress incontinence is described. This tissue has potential advantages of availability, strength, and freedom from side effects.

Prenatal diagnosis of chromosome abnormalities.

It is possible to define a group of prospective parents who are at risk of producing offspring with disability due to chromosomal abnormalities. Such individuals should have evaluation of the 15 or 16 week fetus by karyotype of amniotic fluid cells. The techniques and problems of such diagnostic procedures are discussed.

Changing attendance patterns to sex therapy programs as a function of location and personnel.

This paper explores innovative treatment modalities that may encourage the participation of lower socioeconomic minority clients in sex therapy programs. It suggests the consideration of informal therapeutic settings, flexible hours, and an immediate contact with the therapist. It lends support to the concept that equal time be given to education and communication skills in counseling. It also stresses the necessity of directive yet permissive techniques to bridge the communication gap by identifying areas of commonality, especially when confronted with the lower socioeconomic minority client. The paper compares this approach with a sex therapy approach more oriented to the middle class.

Fetal risk in hyperextension of the fetal head in breech presentation.

An evaluation of the possible etiologic factors in hyperextension of the fetal head in breech presentation and a discussion of management are presented. Our seven cases plus a review of the literature led to the conclusion that hyperextension of the aftercoming head is a dangerous malpresentation that should not be underestimated. For this reason, we strongly suggest an x-ray of all breech presentations in early labor, not only to evaluate pelvic adequacy but also to determine the attitude of the head. In persistent hyperextension, cesarean section is the management of choice.

Copper intrauterine devices--a review of the literature.

PIP: The characteristics of the copper IUD are reviewed by tracing the development of the device, discussing its mechanism of action, evaluating possible systemic effects of copper, and summarizing the clinical data of the copper-7 IUD.^ieng

Comparison of sterilization by tubal ligation and hysterectomy.

A comparison was made between sterilization by hysterectomy and by tubal ligation at the time of cesarean section and as an interval procedure. All operations were done at one institution and, essentially, by the same physician population, allowing for promotion within the residency program. The major deterrent to hysterectomy was the associated high incidence of necessary blood transfusion. However, a hysterectomy does offer the benefits of a permanent and completely effective procedure and the removal of an organ which ultimately may be the source of other problems. If another pathologic condition exists, making ultimate hysterectomy likely, it is the procedure of choice for sterilization, avoiding risks, costs, and the inconvenience of another operation. Methods of elective sterilization must be individualized. If the patient is appraised of the increased risk of hysterectomy and desires this more definitive procedure on the basis of informed consent, the incidence of complications is not prohibitive. These should not deter the well trained surgeon but should mandate use of all available skills, intensive evaluation of the patient, and concerned recognition of the potential adverse consequences.