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Publications


2009

Sharma, VK, Jain A, Mbuya OS.  2009.  Removal of arsenite by Fe(VI), Fe(VI)/Fe(III), and Fe(VI)/Al(III) salts: effect of pH and anions. Abstract

The removal of arsenate and arsenite from drinking water poses challenges, especially when arsenite is present in a significant amount. The removal of arsenite by K(2)FeO(4), K(2)FeO(4)/FeCl(3), and K(2)FeO(4)/AlCl(3) salts was studied at pH 6.5 and at an initial As concentration of 500 microg As(III)L(-1). The arsenite removal in Fe(VI)/Fe(III) and Fe(VI)/Al(III) systems was also examined as a function of pH (6.0-8.0). Arsenite was first oxidized by Fe(VI) to arsenate, which was subsequently removed through adsorption by Fe(III) or mixed Fe(III)-Al(III) oxy/hydroxide phases. Fe(VI)/Al(III) salts had higher removal efficiency of arsenite than Fe(VI) and Fe(VI)/Fe(III) salts. A molar ratio of 6(3/3):1 for Fe(VI)/Al(III) to As(III) decreased arsenite concentration from 500 to 1.4 microg L(-1) at pH 6.5. Arsenite removal increased with a decrease in pH from 8.0 to 6.0 and exhibited less pH dependence in the Fe(VI)/Al(III) system than in the Fe(VI)/Fe(III) system. Aluminum chloride salts performed better than FeCl(3) and FeCl(3)/AlCl(3) salts (Fe:Al=1:1) in removing As(V) from water. Effect of anions (phosphate, silicate, bicarbonate, nitrate, and sulfate) on the arsenite removal by Fe(VI)/Al(III) salts at pH 6.5 was examined. Phosphate, silicate, and bicarbonate ions interfered with the removal of arsenite in water. Nitrate and sulfate had none to minimal effect on arsenite removal. Fe(VI)/Al(III) salts showed a potential for removing arsenite below the current drinking water standard (10 microg L(-1)).

2006

OCHANDA, DRMBUYAS.  2006.  The role of neuro-electrophysiological diagnostic tests in clinical medicine.East Afr Med J. 2006 Jan;83(1):52-60. East Afr Med J. 2006 Jan;83(1):52-60. : The Icfai University Journal of Architecture, Vol. II No.1, February 2010 Abstract
OBJECTIVE: To summarise and discuss the role of neuro-electrophysiological diagnostic tests in clinical medicine. DATA SOURCES: Published original research and reviews to date. STUDY SELECTION: The review was with emphasis on diagnosis of peripheral neuropathic and neuromuscular disorders. DATA EXTRACTION AND SYNTHESIS: On-line and manual library searches provided information and data on which the summaries and discussions were based. Some physicians are not yet aware of some of the tests and some may not know their indications. In this article a review is made of evoked potential tests, nerve conduction tests and electromyography in diagnosis of neurological diseases. An attempt has been made to clearly show their indications, and relative importance. CONCLUSION: Studies clearly show that neuro-electrophysiological tests are important in neurological diagnosis in clinical medicine and are an extension of the physical examination

2005

OCHANDA, DRMBUYAS.  2005.  Dr S.O. Mbuya Review of treatment of epilepsy The Nairobi Journal of Medicine, 2005 Ed.:4. The Nairobi Journal of Medicine, 2005 Ed.:4. : The Icfai University Journal of Architecture, Vol. II No.1, February 2010 Abstract
OBJECTIVE: To summarise and discuss the role of neuro-electrophysiological diagnostic tests in clinical medicine. DATA SOURCES: Published original research and reviews to date. STUDY SELECTION: The review was with emphasis on diagnosis of peripheral neuropathic and neuromuscular disorders. DATA EXTRACTION AND SYNTHESIS: On-line and manual library searches provided information and data on which the summaries and discussions were based. Some physicians are not yet aware of some of the tests and some may not know their indications. In this article a review is made of evoked potential tests, nerve conduction tests and electromyography in diagnosis of neurological diseases. An attempt has been made to clearly show their indications, and relative importance. CONCLUSION: Studies clearly show that neuro-electrophysiological tests are important in neurological diagnosis in clinical medicine and are an extension of the physical examination

2001

OCHANDA, DRMBUYAS.  2001.  Fate of atrazine in sandy soil cropped with sorghum : J Environ Qual. 2001 Jan-Feb;30(1):71-7.. Environ Qual. 2001 Jan-Feb;30(1):71-7.. : The Icfai University Journal of Architecture, Vol. II No.1, February 2010 Abstract
A field study was conducted to determine the fate of atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) within the root zone (0 to 90 cm) of a sandy soil cropped with sorghum [Sorghum bicolor (L.) Moench] in Gainesville, Florida. Atrazine was uniformly applied at a rate of 1.12 kg ai. ha(-1) to a sorghum crop under moderate irrigation, optimum irrigation, and no irrigation (rainfed), 2 d after crop emergence. Bromide as a tracer for water movement was applied to the soil as NaBr at a rate of 45 kg Br ha(-1), 3 d before atrazine application. Soil water content, atrazine, and Br concentrations were determined as a function of time using soil samples taken from the root zone. Atrazine sorption coefficients and degradation rates were determined by depth for the entire root zone in the laboratory. Atrazine was strongly adsorbed within the upper 30 cm of soil and most of the atrazine recovered from the soil during the growing season was in that depth. The estimated half-life for atrazine was 32 d in topsoil to 83 d in subsoil. Atrazine concentration within the root zone decreased from 0.44 kg ai. ha(-1) 2 days after application (DAA) to 0.1 kg a.i. ha(-1) 26 DAA. Negligible amounts of atrazine (approximately 5 microg kg(-1)) were detected below the 60-cm soil depth by 64 DAA. Most of the decrease in atrazine concentration in the root zone over time was attributed to degradation. In contrast, all applied bromide had leached past the 60-cm soil depth during the same time interval.

1996

OCHANDA, DRMBUYAS.  1996.  Peripheral neuropathy in AIDS patients at Kenyatta National Hospital.East Afr Med J. 1996 Aug;73(8):538-40. East Afr Med J. 1996 Aug;73(8):538-40. : The Icfai University Journal of Architecture, Vol. II No.1, February 2010 Abstract
Between June and December 1992 forty AIDS patients as defined by the CDC criteria, admitted to the medical wards of the Kenyatta National Hospital, were studied to determine the prevalence and pattern of peripheral neuropathy. Their mean age was 33 +/- 3 years with a range of 16 to 55 years. Clinical and laboratory assessment were carried out both to confirm peripheral neuropathy and exclude other causes of peripheral neuropathy apart from AIDS. All the patients had nerve conduction and electromyographic studies done. Eighteen patients were asymptomatic while fourteen had both signs and symptoms. The commonest symptom was painful paresthesiae of the limbs (35%) while the commonest sign was loss of vibration sense (60%). When symptoms, signs, and electrophysiological studies were combined, all the patients fitted the definition of peripheral neuropathy. The commonest type of peripheral neuropathy was distal symmetrical peripheral neuropathy (DSPN) (37.5%). PIP: In Kenya, physicians evaluated 40 AIDS patients admitted to Kenyatta National Hospital during June-December 1992 to determine the prevalence and types of peripheral neuropathy in AIDS patients. 75% were 21-40 years old. 18 (45%) of the 40 AIDS patients had symptoms of peripheral neuropathy. Symptoms included increased sensitivity to stimulation (43%), hyperpathia (15%), and muscle or limb weakness (13%). 26 AIDS patients had signs of peripheral neuropathy, especially impaired sense of vibration (60%). 14 of these patients had both signs and symptoms. Electromyographic and nerve conduction velocity revealed peripheral neuropathy in 16 (40%) AIDS patients. The types of peripheral neuropathy included distal symmetrical peripheral neuropathy (37.5%), polyneuropathy, and mononeuritis multiplex. When the symptoms, signs, and electroneurophysiological test findings were considered, all 40 AIDS patients had evidence of peripheral neuropathy.

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