Graphene is essentially a monolayer of sp2 bonded carbon atoms, arranged in a honeycomb lattice. Graphene has in recent years attracted phenomenal interest from researchers in materials science, condensed matter physics, and electronics since its first demonstration in 2004. The importance of graphene research was epitomised by the Nobel prize for physics being awarded to pioneers of the field in 2010. The main topic of this research was the development of epitaxial graphene on silicon carbide (SiC) substrates. The substrate inferred processability of epitaxial graphene enables graphene devices to be fabricated on full wafers using standard semiconductor processing techniques. Biosensor research is a rapidly expanding field. The major driver comes from the healthcare industry but there are also applications for biosensors in the food quality appraisal and environmental monitoring industries. The key advantages of electrochemical biosensors over competing sensor technologies are the low cost of mass production, and ability to make sensors into small compact systems. Smaller, portable sensors allow for the development of point-ofcare medical devices, which can be crucial in fast diagnosis and long-term monitoring of diseases. Graphene channel resistor devices have been fabricated using electron beam lithography and a successfully developed contact metallisation scheme - using Titanium / Gold contacts. The metal-graphene contacts have been characterised using XPS and electrical current-voltage measurements. The graphene channel device has been used as the basis of an electrochemical sensor for human chorionic gonadotropin (hCG), an indicator of pregnancy - which has also been linked to increased risk of several cancers. The immunosensor developed is a promising tool for point-of-care detection of hCG, due to its excellent detection capability, simplicity of fabrication, low-cost, high sensitivity and selectivity.

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Bibliography: leaves 230-294. / xiii, 294 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Analyses in detail a native small fragment of hCG/[beta] hCG subunit, the [beta]-core hCG fragment which is found in large amounts in urine and may be of clinical importance. The aims were to purify the fragment, analyse its protein and carbohydrate structure, develop direct assay methods for its measurement, and to examine it's distribution in body fluids and it's relationship with the intact hCG molecule during pregnancy. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1993

Human chorionic gonodotropin (HCG) affected in various ways cell cultures infected with strains of Rous sarcoma virus (RSV). The cell cultures studied were chick embryo fibroblasts (CEF), normal rat kidney cells infected with temperature-sensitive mutant (LA31-NRK) and a wild type RSV (B77-NRK). HCG increased the rate of transformation and viral titer of CEF cells infected with RSV, but not B77-NRK. HCG increased significantly transformation rates of LA31-NRK, only if the temperature sensitive transformation process was first delayed by incubation at non-permissive temperatures. It is suggested that some postinfective, pretransformational event(s) may operate before viralmediated transformation rates are increased by HCG.

The present investigation was designed to further our understanding of the interaction of pituitary (luteinizing hormone, LH) and placental (chorionic gonadotropin, CG) gonadotropins with the primate corpus luteum. Studies were performed (1) to characterize the LH/CG receptor population in the

RATIONALE OF THE STUDY. To carry out a retrospective chart review of all patients who had a peripartum hysterectomy in hospitals at different levels of health care in the Pietermaritzburg Hospital Complex to examine the incidence and indications for peripartum hysterectomy. METHODS. The charts of 120 cases of peripartum hysterectomy operations performed between January 2003 and January 2008 in the Pietermaritzburg hospital complex of University of KZN were analysed retrospectively. The total number of deliveries were 48 964. The traditional indications, risk factors and associated complications were revisited to determine if there have been changes in current obstetric practice. RESULTS. The overall incidence of peripartum hysterectomy at the Pietermaritzburg complex of hospital was 0.25/1000 deliveries (95% C1 0.2 – 2.9). Uterine atony, bleeding abruption placentae, placentae praevia, uterine rupture following induction and extension of uterine incision into the uterine arteries comprised 87.9% of the indications for peripartum hysterectomy. By far, the most common complications were wound infection and haemorrhage due to difficult haemostasis. Both comprised 61% of complications, others were bladder injury and renal failure. Coagulopathy occurred in 16.7% of cases of whom 2 died due to massive uncontrollable haemorrhage and 26.7% cases had relaparatomy. There were 13.3% of haemorrhagic shock and 5% developed septic shock. All the patients had blood transfusion, 13.3% of patients received platelets in addition to blood. The results showed that 55.8% had previous caesarean sections while 12.5% had VBAC. There were 75.8% live babies. CONCLUSION. The review noted that there has not been a significant change in the incidence and indications for peripartum hysterectomy. The incidence of peripartum hysterectomy in the study 0.25/1000 compared favourably with the findings from similar studies in different parts of the world. Worldwide the incidence of PH ranges from 0.2 to 5.09/1000 deliveries, in our study the incidence was 0.25/1000. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2012.

Thesis (M.S.)--Michigan State University. School of Criminal Justice, 2006 / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 112-116). Also issued in print.

Thesis (M.Sc. (Biochemistry))--Mahidol University, 1984.

Thesis (M.Sc (Biochemistry))--Mahidol University, 1982.

Corpus luteum (CL) dysfunction has been implicated among various factors predisposing early embryonic mortality in cattle. Two experiments were conducted to evaluate the efficacy of using human chorionic gonadotropin (hCG) given either at the time of breeding (day 0) , day 7 or 14 post breeding, in reducing that component of early embryonic mortality caused by CL dysfunction. The aims of experiment 1 were to investigate the effectiveness of using hCG, in inducing the development of accessory CL, their formation and growth, and the effect of such treatments on the function of both the induced and spontaneous CL. Thirty-four lactating Holstein cows were randomly assigned to one of four treatments. A single intramuscular injection of 1000 IU of hCG was given either at the time of breeding (day 0, n=8), day 7 (n=9) or 14 (n=9) post breeding or no hCG given (control, n=8). A real-time ultrasound machine was used to study follicular dynamics and CL growth. The CL and antral follicle diameter was determined using a built-in system of calibrated callipers. Ultrasound scanning was carried out on days 7, 9, 11, 14, 16, 18, 21, 28, 35 and 42 post breeding. Blood and milk samples, for progesterone (P₄) determination using radioimmunoassay, were collected on days coincident with ultrasonography. Diameter of the CL is presented as the sum of the diameter of all luteal tissue in each animal. Differences in CL diameter, milk and plasma P₄ were analyzed using the General Linear Models Procedures while pregnancy data were analyzed using Chi-Square analysis in Statistical Analysis Systems (SAS, version 6.3). Based on the day 7 ultrasound scanning, the incidence of twin ovulations was higher among cows treated on day 0 (3/8) compared to control cows (1/8) and day 7 (1/9). Accessory CL were detected in 7/9 of the day 7-treated cows compared to 4/9 among the day-14 treated cows. Least squares means (LSMeans) for CL diameter were significantly higher (P<0.001) among cows treated with hCG compared to control cows starting at day 7 continually until day 42. Plasma P₄ profiles were significantly higher (P<0.05), at days 18, 35 and 42, in cows treated on day 7 or 14 compared to control cows. The first detectable differences (P<0.05) between hCG treated and control cows, in milk P₄ occurred at day 21 and persisted until day 42. Pregnancy rates were highest among cows treated with hCG on day 7 where 6 of the 9 cows were diagnosed pregnant. Corresponding pregnancy rates for day 0, 14 or control cows, were 4/8, 5/9 and 3/8, respectively. In the second experiment, two trials were conducted at two different farms to investigate the efficacy of using hCG to increase milk P₄ and pregnancy rates. In trial one, 79 lactating Holstein cows were exposed to the treatment protocol described in experiment 1. In addition to the milk sample collection schedule given in experiment 1, a sample was collected on day 0. Milk samples were stored at 4°C and later transported to the UBC laboratories for P₄ analysis. LSMeans for milk P₄ concentrations were different only at days 16 and 18 post breeding. Pregnancy rates were improved (P<0.01) by hCG treatments. The respective pregnancy rates for cows receiving hCG on day 0 (n=20), 7 (n=20), 14 (n=20) or control (n=19) were 25, 35, 35 and 21 %. In the second trial, 121 lactating Holstein cows were randomly assigned to treatments as described earlier. Weekly milk samples were collected from each animal and assayed for P₄ as described above. LSMeans for milk P₄ were significantly different (P<0.05) among groups starting at day 14 until day 42 post breeding. hCG increased pregnancy rates over control cows. The pregnancy rates for cows treated on day 0, 7, 14 and control were 31, 50, 41 and 26 %, respectively. In conclusion, this study revealed that treatment with hCG induced accessory CL development, increased P₄ production and improved pregnancy rates. It is evident, too, that treatment with hCG on day 7 post breeding may have greater potential for improving pregnancy rates not only in dairy and beef cattle but equally beneficial to the embryo transfer programmes. Increased pregnancy rates confirm the hypothesis that CL dysfunction does cost the livestock industry appreciable losses in embryos. / Land and Food Systems, Faculty of / Graduate