Biomedical subjects

J R Díaz

Publications and source records attributed to J R Díaz.

6 recordsLinked to original sources

PubMed2004

Effect of milking pipeline height on machine milking efficiency and milk quality in sheep.

This experiment studied the effect of milking pipeline height (mid- vs. low-level milking system) on milking efficiency and milk composition. The experiment was of 8 wk duration: 2 wk preexperimental period and 6 wk experimental, in crossover design (2 x 2). Ewes were milked in a 2 x 12 milking parlor with 2 milking pipelines set at a milking vacuum of 36 kPa with a pulsation rate of 180 cycle/min and ratio of 50%. Height of the milkline had no effect on yield of milk at the time of milking, yield after stripping, milk composition, SCC, and number of teatcup fall-offs. Nor did milkline height have any effect on milk lipolysis or on the distribution of fatty acids. The level of free fatty acids was higher in evening than in morning milk (60.5 vs. 25.6 mg/L). Likewise, the increase in the degree of lipolysis between the receiver (40.4 mg/L) and the refrigeration tank (45.8 mg/L) underlines the importance of the milk delivery line design. The parameters (time and flow rate) that define the first peak in the milk emission kinetics were statistically different between lines, so care must be taken when comparing milk emission curves from both types of pipeline.

Animals↗

PubMed2003

Micronutrient deficiencies in developing and affluent countries.

Micronutrient deficiencies, also known as 'hidden hunger', are determining and aggravating factors for health status and quality of life. Three nutritional problems that have serious consequences are deficiencies of iron, vitamin A and iodine. It is estimated that in today's world, iron deficiency anemia affects two billion people, mostly women and children. Blindness due to vitamin A deficiency affects 2.8 million children under 5 years of age. Iodine deficiency disorders affect 740 million people. Cuba is employing various programs to deal with these micronutrient deficiencies. Dietary diversification, fortification of foods and supplementation with pharmaceutical preparations are included in Cuba's response to these deficiencies. Urban agriculture is one strategy to increase dietary diversity. The aim is to increase both the availability and consumption of vegetables and fruits. Food fortification takes many forms in Cuba today and various supplementation programs are carried out. The most common supplemental program in the country is the prenatal program. This program provides four essential nutrients: iron, ascorbic acid, vitamin A and folic acid. At present, iodination covers more than 90% of the total amount of salt used for human consumption. Results of research carried out in Cuba have shown that vitamin A deficiency is nonexistent in children up to 7 y of age. Foods and preparations for these programs are delivered gratuitously or at very low prices.

Developed Countries↗

PubMed2003

Influence of pulsation rate on udder health and teat thickness changes in dairy ewes.

In this work on machine milking of ewes, pulsation rates of 120 and 180 cycles per min were compared, both with a pulsation ratio of 50:50 and a vacuum level of 36 kPa, comparing intramammary infection (IMI), somatic cell count (SCC) and teat end thickness changes. To this end, two groups of 20 Manchega ewes were used in a crossover experimental design with two experimental periods of 24 d for each. Bacterial exposure of all teats was increased by dipping them in a suspension of Staphylococcus simulans at four consecutive milkings of each period. Pulsation rate of 180 cycles per min, compared with 120 cycles per min, had no negative effect upon new IMI (11 and 16% of ewes infected, respectively) and SCC. No teat end lesions were observed in those animals milked with the two pulsations assayed. Also, teat thickness changes (-0.38 and -0.36 mm at 120 and 180 cycles per min, respectively) were not affected significantly. Finally, in absence of IMI, the two pulsation rates assayed did not affect the SCC.

Animals↗

PubMed2003

Influence of vacuum level and overmilking on udder health and teat thickness changes in dairy ewes.

The effects of vacuum level and overmilking on udder health were studied in ewes. Vacuum levels of 36 and 42 kPa were assigned to two groups of 23 Manchega ewes in a crossover study design with two experimental periods of 5 wk for each. Moreover, for each ewe, one teat was overmilked 1.5 to 2 min at all milkings during these 10 wk. The milking machine used had a midlevel milkline and pulsation was fixed at 180 cycles per min and a pulsation ratio of 50:50. Bacterial exposure of all teats was increased by dipping them in a suspension of Staphylococcus simulans at eight milkings of each period. New intramammary infections (IMI) were not significantly affected by the vacuum level used (18 and 23% of ewes infected, at 36 and 42 kPa, respectively) or application of overmilking (9 and 11% of half udders infected without and with overmilking, respectively). Likewise, neither factor significantly affected the somatic cell count (SCC) of the milk. Teat thickness changes after milking varied significantly due to the presence of overmilking (-13.6 and -7.4%, in teats not overmilked and overmilked, respectively) but were not affected by vacuum level. At no time were any lesions or variations visibly noted in the teat walls or orifice. So, in this work we were unable to demonstrate that the vacuum and overmilking levels assayed, both used with a pulsation rate of 180 cycles/min, have an important effect on the state of udder health in the short term. Furthermore, it was also observed that, in absence of IMI, the two factors studied did not cause irritation of any kind in the gland that might influence the SCC of the milk.

Animals↗

PubMed2001

Hydroxyapatite spheres with controlled porosity for eye ball prosthesis: processing and characterization.

Porous hydroxyapatite spheres were prepared by a modified gelcasting method producing a ceramic prosthesis with controled porosity. The spheres are approximately 2.2 cm in diameter with a relatively homogeneous pore size distribution from 10 to 40 microm in diameter. The samples were characterized by X-ray powder diffractometry (XRD) and Fourier transform infra-red spectroscopy (FTIR) to identify the phases both prior to and after the gelcasting process. Surface morphology analysis and porosity evaluations were performed with scanning electron microscopy (SEM), while surface area measurements were carried out by the BET technique.

Journal Article↗

PubMedDate not supplied

Transduodenal sphincteroplasty--how we do it.

Transduodenal Sphincteroplasty can be performed in a simple reproducible and low morbidity fashion. The surgical technique used by the Department of Surgery of the Mayagüez Medical Center is presented.

Cholecystectomy↗