Acoustic particle trapping driven by axial primary radiation force in shaped traps.

We study particle trapping driven by the axial primary radiation force (A-PRF) in shaped traps exposed to standing bulk acoustic waves (S-BAW) using numerical simulations and experiments. The utilization of the stronger A-PRF as the main retention force is a consequence of standing-wave formation along the flow direction, instead of the orthogonal direction as in the case of traditionally used lateral-PRF S-BAW trapping setups. The study of particle dynamics reveals that the competition between A-PRF and viscous drag force governs particle trajectory. The ratio of the acoustic energy to the viscous work (ß) provides a general criterion for particle trapping at a distinctive off-node site that is spatially controllable. Particles get trapped for ß≥ß_{cr} at some distance away from the nodal plane and the distance varies as ß^{-c} (c=0.6-1.0). The use of A-PRF as the retention force could potentially allow traditional S-BAW trapping systems to envisage high-throughput advancements surpassing the current standards in cell-handling unit operations.

Evaluation of Iron Store by Serum Ferritin in Healthy Blood Donors of Bangladesh.

Iron stores in the body exist primarily in the form of ferritin. Small amounts of ferritin secreted into the plasma and plasma ferritin is positively correlated with the size of the total body iron stores. The present study conducted to determine the iron status using the serum ferritin level among healthy Bangladeshi blood donors. The present cross sectional study was conducted in the Department of Transfusion Medicine, Dhaka Medical College, Dhaka, Bangladesh from July 2011 to June 2012. Blood donor signed informed consent and has satisfactory pre-donation health assessment and satisfactory post-donation blood test results were included in the study. Full blood counts were performed within 4 hours of collection using an automated haematology analyzer. Serum ferritin was measured using a validated enzyme immunoassay. Data were analyzed using SPSS version 16 (SPPS Incorporation, Chicago, IL, USA). P value <0.05 was considered as statistically significant. Total 100 blood donors were included in the study, among them 88 were male and 12 were female. Mean±SD of the age of the respondents was 26.8±5.9 years with a range of 19 to 45 years. Mean±SD of heamoglobin level (gm/dl) and total count of Red Blood Cell (million/cmm) were 14.1±1.4 and 5.1±0.4 respectively. Mean±SD of serum ferritin level (ng/ml) was 96.4±69.0ng/ml with a range of 4.1ng/ml to 298.7ng/ml. Among the respondents 9.0% had depleted iron store, 7.0 reduced iron store and 84.0% had normal iron store. Among the respondents 5.0% had iron deficiency anaemia in term of serum ferritin level. Statistically significant difference of serum ferritin level observed between male and female and donors with and without history of previous blood donation. Among the healthy blood donors of Bangladesh abnormal serum ferritin is highly prevalent among blood donors specially among female. Monitoring of iron stores by serum ferritin seems justified in order to identify those with depleted iron stores who will benefit from iron supplementation.

Relationship between Serum Iron Profile and Blood Groups among the Voluntary Blood Donors of Bangladesh.

Blood donation results in a substantial iron loss and subsequent mobilization from body stores. Chronic iron deficiency is a well-recognized complication of regular blood donation. The present study conducted to compare the level of serum ferritin, serum iron, total iron binding capacity (TIBC) and percentage transferrin saturation in different ABO and Rhesus type blood groups among the voluntary blood donors of Bangladesh. The present prospective study included 100 healthy voluntary donors attending at Department of Blood Transfusion, Dhaka Medical College, Dhaka between the periods of July 2013 to Jun 2014. From each donor 10mL venous blood sample was taken and divided into heparinized and non-heparinized tubes for determination of hemoglobin (Hb), hematocrit (Hct), serum iron (SI), total iron binding capacity (TIBC) and serum ferritin by standard laboratory methods. Percentage of transferrin saturation (TS) calculated from serum iron and TIBC. Data were analyzed with SPSS (version 16) software and comparisons between groups were made using student's t-test and one way ANOVA. In the present study mean±SD of age of the respondents was 27.2±6.5 years with a range of 18 to 49 years and 81.0% were male and 19.0% were female. Among the donors 18.0% had blood group A, 35.0% had blood group B, 14.0% had blood group AB and 33.0% had blood group O. Among the donors 91.0% had rhesus positive and 9.0% had rhesus negative. Donors with blood group O had lowest haemoglobin, serum iron and transferring saturation levels. Donors with blood group A had highest TIBC level. Donors with blood group B had lowest serum ferritin level. An independent samples 't' test showed statistically significant difference in serum ferritin and percentage transferrin saturation between blood group AB and blood group O and in percentage transferrin saturation between blood group B and blood group O. One way ANOVA showed that there is no significant difference in haemoglobin, serum iron, serum ferritin and percentage transferring saturation in different ABO and Rh blood grouping categories. Blood donors with blood group O had lowest haemoglobin, serum iron and transferring saturation levels and donors with blood group A had highest TIBC level. Blood donors with blood group B had lowest serum ferritin level. The understanding of the different blood groups ability to retain iron in their system can give an insight into their ability to handle the disease iron deficiency anaemia.

Utilisation pattern of blood in a teaching hospital of Kolkata.

An annual utilisation of blood transfusion services at several depts. of R.G. Kar Medical College and Hospital, Kolkata were assessed among a sample of 3122 patients selected by Systematic Random Sampling Technique from the register made available in the blood bank there. Record analysis revealed that overall 79.4% of supplied blood units were actually transfused, wastage of 21.6%. Wastage was maximum in the Department of Gynae & Obstetrics (33.11%) and Surgery (32.87%). Only single unit of blood was requisitioned and transfused for 5.44% & 30.90% of the patients respectively. Most common indications of blood transfusion were for surgical cases (37.92%), followed by anaemia (34.80%) and haemorrhage (26.92%). The use of blood and blood products merit attention, appraisal and instructional guiding accordingly.

A patient with optic pathway glioma, scoliosis, Chiari type I malformation and syringomyelia: is it Neurofibromatosis type 1?

A 22 years old girl had features of optic pathway glioma, scoliosis, Chiari type 1 malformation and cervical syringomyelia. She had no cutaneous lesions. We considered this combination to be more than coincidental and argue in favour of considering the case as a variant form of Neurofibromatosis type 1. The relevent literature in favour of our contention has been reviewed.