Showing papers by "National University of Malaysia published in 1984"

Tendon excursion of wrist movers

Abstract: In mechanical terms, the wrist joint is moved by a system of effective pulleys and levers influenced by the anatomic structures present at the wrist. Assuming that the tendon excursion in a cadaver would reflect the excursion of the corresponding tendon in a live hand moving the wrist through the same arc of motion, this study measures the excursions of the wrist tendons during flexion-extension motion and radioulnar deviation in different positions of forearm rotation and relates tendon function to anatomic configuration. Two separate experiments were performed to measure the tendon excursion, in one of which the data were collected manually and in the other a system of computer-aided data collection was used.

Internal carotid artery aneurysm: A singular anomaly

Abstract: A 9-year-old Indian boy was found to have an aneurysm of the left internal carotid artery. The vessel was heavily atherosclerosed, and the distal segment of the artery was tortuous and dilated. Serum lipid estimations showed the presence of type IIB hyperlipoproteinemia, with evidence of the disease in the patient's identical twin sibling and 37-year-old father. There was also a marginal increase in serum triglycerides in a 4-year-old younger brother. The patient's 29-year-old mother was unaffected. The patient had suffered hemolytic disease as a newborn, which resulted in kernicterus and subsequent mental retardation. This incident is considered to have been the result of a proven glucose-6-phosphate dehydrogenase deficiency. The aneurysm was resected and arterial continuity was ensured by using an end-to-end anastomosis. Post-operative blood flow studies showed normal flow patterns in the reconstituted artery. Postoperatively, the patient's mental performance increased dramatically; it is hypothesized that such progress is the consequence of an improvement in the blood supply to the limbic system, following the operative procedure.

Effects of thyroxine treatment on contractions of soleus muscles of anaesthetized cats.

Abstract: SUMMARY 1. The effects of chronic thyroxine treatment on cat soleus muscle contractions were studied. 2. Maximum twitch tension, contraction time, half relaxation time and tensiontime integral of maximal twitches of the soleus muscles of thyroxine treated cats were significantly decreased. Consequently, there was a decrease in tension and degree of fusion of incomplete tetanic contractions of the soleus muscle. The maximum tetanic tension was not statistically significantly changed, suggesting that the effects may be due to a decrease in the duration of the active state of the muscle. 3. Isoprenaline given intravenously during incomplete tetanic contractions of the soleus muscle caused a statistically significant depression of tension in the control group but not in the thyroxine treated group. This further suggests reduction in the duration of the active state of soleus muscles of thyroxine treated cats. 4. Propranolol injected chronically with thyroxine reversed or prevented the depression of tension caused by thyroxine treatment, suggesting the involvement of β-adrenoceptors in these effects. 5. The decrease in tension and degree of fusion during incomplete tetanic contractions of the thyroxine treated soleus could be responsible, at least partly, for the muscle weakness and tremor of thyrotoxicosis. Cyclic AMP may possibly be the mediator of these effects.

Quarry site selection in Malaysia

Abstract: To cater for the demands for various rock aggregates for the numerous engineering construction projects in Malaysia, such as dams, highways, housing developments, etc., the location of suitable quarry sites at or in the immediate vicinities of the project sites has been the responsibility and constant duty of the engineering geologist. This paper summarises the various engineering geologic factors that are considered in the location of potential quarry sites, in particular with reference to the practices in Malaysia. The factors considered include, among other things, the lithology, degree of weathering, overburden soil cover, geologic structures such as jointing or fracturing, engineering properties of the aggregates, operational difficulties such as benching, blasting and rock slope stability, and environmental considerations. Various case studies from Malaysia are presented, emphasis being on the problems that are often encountered here such as the high degree of weathering, inability to do benching in quarry sited on limestone cliffs, conflict with other landuse, etc.

Daily cycles of suspended particulate air pollution in the kelang valley region, peninsular malaysia

Abstract: Sinopsis Kertas ini mengemukakan hasil kajian mengenai variasipola pencemaran partikel ampaian dz empat buah stesen d i kawasan bandar, Wihyah Lembah Kelang. Hasil &an mmunjukkan bahawa meskipun kemuncak paras pencemaran pada waktupagi danpetang itu agakjelas kelihatan bagi stesen-stesenyangjauh dari $an raya yang sesak dengan kenderaan, dun didapati serupa dengan yang diperhatikan d i negara-negara garisan lintang pertengahan, tetapi bagi stesenstesen yang terletak di pusat bandar dun berhampiran dengan jalan raya yang sesak, bilangan kemnncaknya adalah lebih daripada dua. Pola ini tidak dapat dijelaskan sonata-mata berasaskan kepada mekanisma fumigasz sahaja. Penulis menyamnkan bahawa di kawasan pusat bandar pengaruh lalu lintas adalah penting selain daripada pengamh fumkasi itu.