Influence of chitosan properties and operating parameters on the flocculation efficiency and harvesting of microalgae (Scenedesmus sp.).

Physicochemical and structural characteristics of chitosan prepared from Deep-sea shrimp (DCs), including degree of deacetylation (DD), molecular weight (Mw), viscosity, crystallinity index (CrI) and surface morphology were compared with a commercial chitosan (CCs). The DCs had a higher DD of 81.33 ± 0.40 %, whereas the CCs had a lower DD of 74.62 ± 0.64 %. Additionally, the DCs exhibited a lower Mw of 192.47 ± 2.5 kDa and viscosity of 646.00 ± 4.00 cP compared to the CCs, which had a Mw of 202.44 ± 0.28 kDa and viscosity of 689.67 ± 5.91 cP. This study investigated the influence of chitosan properties, particularly DD and Mw on the harvesting of Scenedesmus sp. along with the chitosan dosage, pH of the culture medium, mixing speed and time. Under optimal operating conditions, the microalgae removal efficiency of the DCs reached a significantly higher level (94.71 ± 0.20 %) compared to that of CCs (88.25 ± 0.41 %). Chitosan with a higher DD and low Mw demonstrated superior flocculation efficiency. The results highlight the significance of DD and Mw of chitosan and its influence on the flocculation of microalgae, providing valuable insights for optimizing the harvesting process with the non-toxic and natural flocculent, chitosan.

Complete Heparin Reversal by Protamine during Off-Pump Coronary Artery Bypass Surgery (OPCAB): A Necessity or Myth?

In our country majority of the coronary artery bypass surgery (CABG) are done off-pump and was reported having excellent clinical outcome along with cost efficiency by various investigators. Heparin is commonly used as most effective anticoagulant, and protamine sulfate is now generally used to reverse the anticoagulant action of heparin. While under dosing of protamine may result in incomplete heparin reversal and prolonged anticoagulation, protamine overdosing is associated with impaired clot formation exerted by the intrinsic anti-coagulation properties of protamine itself, moreover protamine administration is associated with mild to severe cardiovascular and pulmonary complications. Apart from traditional full neutralization of heparin now-a-days, half dose protamine was also introduced showing good outcome regarding lower activated clotting time (ACT), overall, less surgical bleeding with less transfusion. This comparative study was designed to detect differences between traditional and decreased protamine dosing in Off-Pump Coronary Artery Bypass (OPCAB) surgery. Four hundred (400) patients who underwent Off-Pump Coronary Artery Bypass Surgery (OPCAB) surgery at our institution over a period of 12 months were analyzed and were divided into two groups. Group A- received 0.5mg of protamine per 100 unit of heparin; Group B-received 1.0mg of protamine per 100 unit of heparin. ACT, blood loss, hemoglobin and platelet count units of blood and blood product transfusion requirements, clinical outcome and hospital stay were assessed in each patient. This study showed that 0.5mg of protamine per 100 unit of heparin was always able to reverse the anticoagulant effect of heparin with no significant difference in hemodynamic parameters, amount of blood loss and requirements of blood transfusion in between the groups. A standard protamine dosing formula (protamine-heparin at ratio of 1:1) adequate for on-pump cardiac surgical procedures significantly overestimates protamine requirements for OPCAB. Patients treated with decreased protamine do not appear to have adverse outcomes in terms of post-operative bleeding.

Investigations on Crystalline Perfection, Raman Spectra and Optical Characteristics of Transition Metal (Ru) Co-Doped Mg:LiNbO3 Single Crystals.

Congruent lithium niobate single crystals with a Ru:Mg co-dopant have been successfully grown using the Czochralski technique from the melt containing 0.02 mol % Ru with Mg of two varied concentrations (4.0 and 6.0 mol %). The effects of Ru and Mg co-doping on the crystalline quality were determined by high-resolution X-ray diffractometry, which confirmed that the crystalline quality is good and that the dopants are statistically distributed in the crystal. The Raman scattering analysis shows no change in the lattice vibration except a slight change in the peak width and intensity due to more asymmetry in the molecular charge, which leads to enhancement of the polarizability. The optical transmission spectra indicate that both the crystals have high optical transparency in the visible region, with a shift of the absorption edge toward shorter wavelengths, as compared to un-doped LN. The weak absorption band observed below 400 nm is attributed to Ru ions. The influence of co-doping in the electronic band gap energies is calculated by the Tauc relation. The refractive index is measured by using a prism coupler at two wavelengths (532 and 1064 nm). The calculated absorption coefficients and direct and indirect band gap energies for both the samples are found to be nearly the same within experimental error. A decrease in the birefringence is observed for the Ru:Mg(6 mol %) doped sample. The observed slight reduction in refractive indices with Ru:Mg co-doping is consistent with a rise in band gap energy, which is related to the change in absorption edge to the lower wavelength. The second harmonic generation (SHG) efficiency is measured by the Kurtz and Perry powder method, and a decrease in SHG efficiency for Ru:Mg(6 mol %) is observed.

Classification of motor imagery using a time-localised approach.

Brain-computer interface (BCI) is getting increasing attention where classification of motor imagery (MI) using electroencephalography (EEG) signal plays a vital role. In traditional EEG-based BCI setup, after applying pre-processing like band-pass filtering and spatial filtering, features are extracted and are fed to the classifier. However, most of the traditional features are extracted from a single time window, which is usually the full-time frame of a cue-based MI signal. Such features are usually statistical characteristics like log-variance of the whole-time signal. Thus, the information, which is localised in time and crucial for subject-specific MI classification, is not best captured. In this work, a new time-localised approach is proposed where multiple time windows are used for feature extraction. We have developed a number of feature representations using those time windows. Our experimental results corroborate that the proposed approach can achieve higher accuracy of classification when compared to methods using conventional features using the same platform.

A space-frequency localized approach of spatial filtering for motor imagery classification.

Classification of Motor Imagery (MI) signals is the heart of Brain-Computer Interface (BCI) based applications. Spatial filtering is an important step in this process that produce new set of signals for better discrimination of two classes of EEG signals. In this work, a new approach of spatial filtering called Space-Frequency Localized Spatial Filtering (SFLSF) is proposed to enhance the performances of MI classification. The SFLSF method initially divides the scalp-EEG channels into local overlapping spatial windows. Then a filter bank is used to divide the signals into local frequency bands. The group of channels, localized in space and frequency, are then processed with spatial filter, and features are subsequently extracted for classification task. Experimental results corroborate that the proposed space localization helps to increase the classification accuracy when compared to the existing methods using spatial filters. The classification performance is further improved when frequency localization is incorporated. Thus, the proposed space-frequency localized approach of spatial filtering helps to deliver better classification result which is consistently 3-5% higher than traditional methods.

Hemoprotozoa and Anaplasma spp. in rodents and shrews of Bangladesh.

Hemoprotozoans are important pathogens of animals and humans, among which some species have zoonotic significance. The prevalence of different hemoprotozoa and Anaplasma spp. in larger mammals have been reported from different regions of the world. But, very few studies have been conducted to estimate the prevalence of hemoprotozoa in rodents and shrews of South-East Asia. The study assessed the prevalence of hemoprotozoa and Anaplasma spp. in rodents and shrews of Bangladesh. Blood samples (n=451) were collected from rodents and shrews between June 2011 and June 2013 and July-December 2015 from 4 land gradients of Bangladesh. Giemsa-stained blood smears revealed that 13% of animals were harboring hemoprotozoa (4.7% Babesia spp., 0.67% Plasmodium spp.), and Anaplasma spp. (7.5%). The study may serve as a guide for future hemoparasitic research of rodents and shrews.

Hemoprotozoa and Anaplasma spp. in rodents and shrews of Bangladesh

@#Hemoprotozoans are important pathogens of animals and humans, among which some species have zoonotic significance. The prevalence of different hemoprotozoa and Anaplasma spp. in larger mammals have been reported from different regions of the world. But, very few studies have been conducted to estimate the prevalence of hemoprotozoa in rodents and shrews of South-East Asia. The study assessed the prevalence of hemoprotozoa and Anaplasma spp. in rodents and shrews of Bangladesh. Blood samples (n=451) were collected from rodents and shrews between June 2011 and June 2013 and July-December 2015 from 4 land gradients of Bangladesh. Giemsa-stained blood smears revealed that 13% of animals were harboring hemoprotozoa (4.7% Babesia spp., 0.67% Plasmodium spp.), and Anaplasma spp. (7.5%). The study may serve as a guide for future hemoparasitic research of rodents and shrews.

Elevated levels of serum uric acid and insulin resistance are associated with nonalcoholic fatty liver disease among prediabetic subjects.

Background: Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of insulin resistance and serum uric acid (SUA) levels seemed to be elevated during this disorder. There is a paucity of data regarding the association of SUA with NAFLD in prediabetes. In this context, the present study has been undertaken to investigate this association. Methods: In a cross-sectional analytical design, a total of 110 prediabetic subjects [M/F; 63/47, age in ranges, 45 (25-68)] were recruited in the study and divided into non NAFLD (n = 62) and NAFLD (n = 48) group after examined with ultrasonogram. Insulin resistance (HOMA-IR) was calculated by homeostasis model assessment. Results: NAFLD subjects had significantly higher levels of SUA compared to non NAFLD subjects (6.10 ± 1.42 vs. 5.38 ± 1.14, p = 0.004). They also had significantly higher levels of HOMA-IR (2.4 ± 1.09 vs. 1.4 ± 0.45, p < 0.001). In binary logistic regression analysis, HbA1c (OR = 3.505, p = 0.002), SUA (OR = 1.514, p = 0.023) and HOMA-IR (OR = 1.478, p = 0.029) were found to be significant determinants of NAFLD after adjusting the effects of BMI and triglyceride (TG). In multiple linear regression analysis, SUA showed significant positive association with HOMA-IR (ß = 0.355, p = 0.027) and TG (ß = 0.325, p = 0.033) after adjusting the effects of BMI and HbA1c. Conclusions: Increased levels of serum uric acid are significantly associated with NAFLD and this association seemed to be mediated by insulin resistance among prediabetic subjects.

The analgesic requirement after thyroid surgery under general anaesthesia with bilateral superficial cervical plexus block.

In this study we evaluated the analgesic efficacy of bilateral superficial cervical plexus block after thyroid surgery. Sixty patients were assigned to two groups. General anesthesia was induced with 2mg/kg propofol, 0.1mg/kg vecuronium and 1.5µg fentanyl IV for both group. After endotracheal intubation, bilateral superficial cervical plexus block with 0.25% bupivacaine 15ml in each side was performed in Group I. In Group II (control) no regional block was administered. Intravenous on demand analgesic was used to evaluate postoperative analgesic requirement. Neither visual analog scale scores nor intravenous analgesics doses were different between the groups. The first analgesic requirement time in Group I was significantly longer than for the control group. The incidence of nausea and vomiting was significantly lower in Group I than Group II. We concluded that bilateral superficial cervical plexus block with 0.25% bupivacaine did not decrease analgesic requirement after thyroid surgery.

Assessment of renal function by estimation of fractional excretion of sodium in asphyxiated newborns.

This case control study was conducted in Neonatal unit of Dhaka Shishu (Children) Hospital to assess the validity of fractional excretion of sodium (FENa) as a reliable renal function test in asphyxiated newborns. Seventy five appropriate newborns aged between 0-120 hours were randomized in two groups, (Group I; n=50, cases or study group) and (Group II; n=25, controlled group). Blood urea, serum creatinine, serum electrolytes, urinary electrolytes, creatinine, osmolalities, specific gravity, FENa were estimated. Blood urea, Serum creatinine and FENa are increased in perinatal asphyxia. Controls were selected from newborns who had spontaneous breathing immediately after birth and with Apgar score >8 to 10 at 5 minutes. Mean blood urea and serum creatinine were raised in asphyxiated newborn. Blood urea mean±SD was 7.1±3.1mmol/L and serum creatinine mean±SD was 120.8±73.6µmmol/L. Thirty four percent (34%) patients had raised level of blood urea and serum creatinine both, 18% patients had raised (>2.5%) FENa and 48% patients had raised blood urea in asphyxiated newborns. Hyponatremia was also found in asphyxiated newborns. Urinary sodium and creatinine excretion were also higher in the asphyxiated newborns than non asphyxiated newborns. Urinary volume and osmolality were similar in cases and controls. In this study 24% patients died, of which 62.5% were in HIE stage 3, 4.16% were in HIE stage 2 and 1% was in HIE stage 1. Elevated level of serum creatinine (130.0±60.0) and FENa (2.9±1.4) were found in dead patients. Oliguria (0.99±0.6) was also found in dead asphyxiated newborns. Increase in fractional excretion of sodium (FENa) is shown to be directly related to the degree of renal impairment which is again directly related to the degree of asphyxia in the newborns. FENa can be used as an indicator of renal tubular dysfunction in the asphyxiated newborns.

Tubercular lymphadenitis - diagnostic evaluation.

Tuberculosis is one the commonest disease affecting peripheral lymph node and cervical tubercular lymphadenitis are frequently encountered in Otolaryngological practice. Three hundred fifty six (356) cases of Fine Needle Aspiration for Cytology (FNAC) positive tubercular lymphadenitis were studied from January 2006 to December 2008. FNAC positive but histopathologically negative cases were excluded from the study. Among 356 cases of FNAC positive cervical lymphadenopathy 300 cases (84.27%) were confirmed tuberculosis on histopathological examination. Remaining 50 cases (15.73%) were diagnosed as nontubercular lymphadenitis where nonspecific lymphadenitis was the commonest finding 34(9.55%) followed by metastatic carcinoma 7(1.97%), lymphoma 6(1.08%), Kikuchiz's disease 6(1.08%), Kala-Azar 2(0.56%) & Leukemia 1(0.28%). Most of the patients presented with only multiple lymph node swelling with other symptoms, such as fever 18(5.06%), pain (15.7%), tenderness 53(14.88%), weight loss 29(8.14%), anorexia 33(9.26%). Following observations are evident from this study: i) Disease is comparatively common between 12-35 years ii) Multiple matted/discrete lymph nodes are the earliest presentation iii) Multiple lymph node is the most consistent finding for clinical diagnosis. iv) Very few patients have constitutional symptoms v) Suppuration with or without abscess formation although confirms the diagnosis even then certainty is very essential. Though the evidence of cervical tuberculosis was thought to be decreasing in developing countries the real picture seems to be different. Random survey among the whole population was not done in any country rather hospital based laboratory research was made.

Multilayer SOM with tree-structured data for efficient document retrieval and plagiarism detection.

This paper proposes a new document retrieval (DR) and plagiarism detection (PD) system using multilayer self-organizing map (MLSOM). A document is modeled by a rich tree-structured representation, and a SOM-based system is used as a computationally effective solution. Instead of relying on keywords/lines, the proposed scheme compares a full document as a query for performing retrieval and PD. The tree-structured representation hierarchically includes document features as document, pages, and paragraphs. Thus, it can reflect underlying context that is difficult to acquire from the currently used word-frequency information. We show that the tree-structured data is effective for DR and PD. To handle tree-structured representation in an efficient way, we use an MLSOM algorithm, which was previously developed by the authors for the application of image retrieval. In this study, it serves as an effective clustering algorithm. Using the MLSOM, local matching techniques are developed for comparing text documents. Two novel MLSOM-based PD methods are proposed. Detailed simulations are conducted and the experimental results corroborate that the proposed approach is computationally efficient and accurate for DR and PD.

Alcaligenes xylosoxidans and Propionibacterium acnes postoperative endophthalmitis in a pseudophakic eye.

PURPOSE: To report a case of persistent polymicrobial postoperative endophthalmitis caused by Alcaligenes xylosoxidans and Propionibacterium acnes in a pseudophakic eye. A. xylosoxidans is a gram-negative bacteria resistant to most antibiotics. METHODS: Case report. RESULTS: A 72-year-old man presented with clinical signs of endophthalmitis on the first postoperative day after a phacoemulsification procedure with posterior chamber intraocular lens, left eye. Initial treatment included topical, subconjunctival, and oral antibiotics. After initial clearing, there was recrudescence of infection on postoperative day 37 that prompted referral of the patient to the Cullen Eye Institute. Treatment at that time included anterior chamber and vitreous taps with intravitreal antibiotic injections. Complete pars plana vitrectomy and intraocular lens explantation were eventually required because of persistent infection with a resistant organism. Cultures from the first procedure grew A. xylosoxidans and P. acnes. Cultures from the vitrectomy grew only A. xylosoxidans. At the final follow-up visit 6 months after the initial procedure. The eye was without inflammation with best-corrected visual acuity of 20/40. CONCLUSION: Both A. xylosoxidans and P. acnes can cause chronic progressive endophthalmitis after cataract extraction often resistant to corrective antibiotic therapy. Successful intervention may require complete vitrectomy with intraocular lens and capsule removal.

Susceptibility of the malaria vectors to insecticides in Bangladesh.

Insecticide susceptibility tests with diagnostic dosages of 4% DDT and 5% malathion concentrations conducted at field sites on the two important principal malaria vectors namely, Anopheles dirus and An. philippinensis have been reported. They are found to be susceptible to DDT and malathion. The implication of the use of insecticides in controlling malaria is also discussed.

Intracranial aneurysm surgery in Bangladesh.

In this study of 1000 cerebrovascular disease patients, the commonest age are 50 to 70 years with male predominance. The urban patients are large in number and the risk factors are sedentary life, stress and strain, smoking, and hypertension. The patients are more chronic than acute and transport facilities are poor. Fifteen percent are hemorrhagic stroke, some of them may be due to intracranial aneurysm. In the absence of proper diagnostic facilities and adequate neurosurgeons, infrequent surgical treatment, and lack of statistics of intracranial aneurysm, this study may be a basis for further study of aneurysmal surgery in Bangladesh.

Biological control of mosquito larvae by Guppy fish.

Predation potentiality of a biological control agent, the guppy fish, Poecilia reticulata (= Lebistes reticulatus), was studied over the mosquito larvae under laboratory conditions. The third instar larvae of Culex quinquefasciatus mosquito were used as prey. The average consumption rate was 41.0 per day per fish. The female fish was more active (54.9) than male ones (27.0). The feeding activity was found to be higher at higher water temperature. The study suggests that this fish could be used, after careful field trial, as a promising and sustainable biological control agent in controlling filariasis and other mosquito-borne diseases.

A double-blind, randomised comparison of fluvoxamine with dothiepin in the treatment of depression in elderly patients.

The efficacy and tolerability of the selective 5-HT reuptake inhibitor fluvoxamine were compared with the tricyclic dothiepin in 52 elderly (age greater than 64 years) hospital patients in a multi-centre double-blind randomised trial. Patients met DSM-III criteria for 'major depressive episode' and scored greater than 29 on the Montgomery Asberg Depression Rating Scale (MADRS) after a one-week placebo baseline. Active treatment was for six weeks. The dosage of both drugs was 50 mg nocte for three days, 100 mg nocte for the remainder of the first week, thereafter increasing to a maximum of 200 mg/day according to response/tolerance. MADRS scores improved by 63.5% with fluvoxamine and 60.0% with dothiepin; there were no significant differences between treatments at any assessment. Nausea, dizziness, headache, somnolence and constipation in both groups, plus dry mouth and asthenia in the dothiepin group were more frequent than single reports. Two patients in each group discontinued treatment owing to unwanted effects. There were no clinically significant changes in haematological, biochemical or cardiovascular parameters.

Presence of endogenous inhibitor of aromatic L-amino acid decarboxylase in monkey serum.

In the course of our studies on the developmental changes of aromatic L-amino acid decarboxylase (AADC) in the serum of Japanese monkeys (Macaca fuscata fuscata), we found the presence of an endogenous inhibitor of AADC in all stages of monkey life. This inhibitor inhibited the serum enzyme activity completely with L-5-hydroxytryptophan (L-5-HTP) as substrate, while the activity was partially inhibited with L-DOPA as substrate. The inhibitor was non-dialyzable, but it could be removed from the monkey serum by DEAE-Sephacel chromatography. After this treatment AADC activities could be detected in the monkey serum by using both L-DOPA and L-5-HTP as substrates. Moreover, the total activity for L-DOPA was augmented by 3-fold in the serum after the removal of the inhibitor. Serum AADC was partially purified from monkey and compared with that of rat using both L-DOPA and L-5-HTP as substrates, but the ratio of the activities for the two substrates did not change significantly in each fraction during purification from either monkey or rat serum.