Effect of drying methods and storage with agro-ecological conditions on phytochemicals and antioxidant activity of fruits: a review.

Choice of drying methods significantly impacts the nutritive and non-nutritive compounds in fruits and vegetables. Phytochemicals such as total phenolics and total flavonoids are non-nutritive bioactive compounds and are found in plants which are of important value due to their antioxidant properties in minimizing the oxidation reaction. However, drying and storage conditions and duration significantly affect these important quality attributes. There is currently no review article on the impact of the drying and storage conditions on these quality attributes. Therefore, the aim of this review paper is to investigate the impact of drying methods on these important phytochemicals and their antioxidant activity on dried products during the storage period. Different drying methods cause desirable and undesirable changes to dried products both physically and chemically. It is found that during the drying process at various temperature ranges from 40 to 80 °C, chemical changes occurs which affects the phenolic and the flavonoid content of dried products to increase or decrease. The increase in antioxidant activity after drying is also due to oxidized polyphenols and Maillard reaction products. This results to changes in the antioxidant potential of the dried food product and its impact on the shelf life.

Performance of Graphite-Dispersed Li2CO3-K2CO3 Molten Salt Nanofluid for a Direct Absorption Solar Collector System.

Considered to be the next generation of heat transfer fluids (HTFs), nanofluids have been receiving a growing interest over the past decade. Molten salt nanofluids have been shown to have great potential as an HTF for use in high temperature applications such as direct absorption solar collector (DAC) system. Very few studies using molten salt nanofluids as the HTF in a DAC receiver can be found in the open literature. This study aimed to develop a 3D computational fluid dynamics model of the receiver of a DAC using graphite-nanoparticle-dispersed Li2CO3-K2CO3 molten salt nanofluid to investigate the effects of design and operation parameters on receiver performance. Receiver total efficiency using Li2CO3-K2CO3 salt was compared with that using solar salt nanofluid. Spectral properties of the base fluid and nanoparticles were modeled as wavelength-dependent and the absorption of the solar radiation was modeled as a volumetric heat release in the flowing heat transfer fluid. Initial results show that the receiver efficiency increases with increasing solar concentration, decreasing nanoparticle volume fraction, and decreasing receiver length. It was also found that the Carnot efficiency increases with increasing receiver length and nanoparticle volume fraction, and decreasing solar concentration and inlet velocity. Comparative study shows that solar salt HTF could provide higher total efficiency. However, a higher operating temperature of Li2CO3-K2CO3 will allow for a greater amount of thermal energy storage for a smaller volume of liquid.

Microwave-convective drying of food materials: A critical review.

Microwave convective drying (MCD) is gaining increasing interest due to its unique volumetric heating capability and ability to significantly reduce drying time and improve food quality. The main objective of this paper is to discuss, critically analyze and evaluate the recent advances in MCD and suggest the future directions in this field. The main focus of this paper is the mathematical modeling and experimental investigations in microwave convective drying of food materials. Recent developments in mathematical modeling of MCD is discussed and existing experimental setup and their advantages and disadvantages are discussed and analysed. Long drying time is a concern in food industries. Reductions in drying time by applying MCD compared to convection drying are calculated and discussed. It was apparent that the proper integration of mathematical modeling and experimental technique is the best way to maximize the advantages of this drying method. Although a plethora of research is being carried out on this topic, there is still need for research to develop fundamental modeling to optimize the process parameters and scale up this technology for the industrial application. Overall, the review provides an in-depth insight into the latest development of MCD and its mathematical modeling approaches and will hopefully serve to inspire future work in the field.

Quality of plant-based food materials and its prediction during intermittent drying.

In most drying processes, several physical, chemical and nutritional modifications take place in food products. Innovative drying techniques such as intermittent drying can enhance the quality of dehydrated products effectively and efficiently. Intermittent drying is a technique where drying conditions are changed through varying the drying air temperature, humidity, velocity, pressure, or even mode of heat input. This drying technique has been successfully applied to overcome the problems of conventional drying systems such as longer time consumption, case hardening, lower energy efficiency and poor-quality attributes. However, as the effect of intermittent drying on food quality is not yet well understood, a comprehensive study of quality change during intermittent drying is crucial. The main aim of this paper is to present a thorough review of the potential effect of intermittent drying methods on physical, chemical, nutritional, and stability characteristics of plant-based food material. It is found that application of intermittency using different drying systems has a significant effect on product quality and its stability. In addition, a comprehensive review on existing models of physio/biochemical kinetics for food drying is presented. Finally, the paper is concluded with the discussion of the current challenges and future directions of intermittent drying for producing high-quality dried food products.

Performance Investigation of High Temperature Application of Molten Solar Salt Nanofluid in a Direct Absorption Solar Collector.

Nanofluids have great potential in a wide range of fields including solar thermal applications, where molten salt nanofluids have shown great potential as a heat transfer fluid (HTF) for use in high temperature solar applications. However, no study has investigated the use of molten salt nanofluids as the HTF in direct absorption solar collector systems (DAC). In this study, a two dimensional CFD model of a direct absorption high temperature molten salt nanofluid concentrating solar receiver has been developed to investigate the effects design and operating variables on receiver performance. It has been found that the Carnot efficiency increases with increasing receiver length, solar concentration, increasing height and decreasing inlet velocity. When coupled to a power generation cycle, it is predicted that total system efficiency can exceed 40% when solar concentrations are greater than 100×. To impart more emphasis on the temperature rise of the receiver, an adjusted Carnot efficiency has been used in conjunction with the upper temperature limit of the nanofluid. The adjusted total efficiency also resulted in a peak efficiency for solar concentration, which decreased with decreasing volume fraction, implying that each receiver configuration has an optimal solar concentration.

Prediction of porosity of food materials during drying: Current challenges and directions.

Pore formation in food samples is a common physical phenomenon observed during dehydration processes. The pore evolution during drying significantly affects the physical properties and quality of dried foods. Therefore, it should be taken into consideration when predicting transport processes in the drying sample. Characteristics of pore formation depend on the drying process parameters, product properties and processing time. Understanding the physics of pore formation and evolution during drying will assist in accurately predicting the drying kinetics and quality of food materials. Researchers have been trying to develop mathematical models to describe the pore formation and evolution during drying. In this study, existing porosity models are critically analysed and limitations are identified. Better insight into the factors affecting porosity is provided, and suggestions are proposed to overcome the limitations. These include considerations of process parameters such as glass transition temperature, sample temperature, and variable material properties in the porosity models. Several researchers have proposed models for porosity prediction of food materials during drying. However, these models are either very simplistic or empirical in nature and failed to consider relevant significant factors that influence porosity. In-depth understanding of characteristics of the pore is required for developing a generic model of porosity. A micro-level analysis of pore formation is presented for better understanding, which will help in developing an accurate and generic porosity model.

Multiphase porous media modelling: A novel approach to predicting food processing performance.

The development of a physics-based model of food processing is essential to improve the quality of processed food and optimize energy consumption. Food materials, particularly plant-based food materials, are complex in nature as they are porous and have hygroscopic properties. A multiphase porous media model for simultaneous heat and mass transfer can provide a realistic understanding of transport processes and thus can help to optimize energy consumption and improve food quality. Although the development of a multiphase porous media model for food processing is a challenging task because of its complexity, many researchers have attempted it. The primary aim of this paper is to present a comprehensive review of the multiphase models available in the literature for different methods of food processing, such as drying, frying, cooking, baking, heating, and roasting. A critical review of the parameters that should be considered for multiphase modelling is presented which includes input parameters, material properties, simulation techniques and the hypotheses. A discussion on the general trends in outcomes, such as moisture saturation, temperature profile, pressure variation, and evaporation patterns, is also presented. The paper concludes by considering key issues in the existing multiphase models and future directions for development of multiphase models.

Multi-scale model of food drying: Current status and challenges.

For a long time, food engineers have been trying to describe the physical phenomena that occur during food processing especially drying. Physics-based theoretical modeling is an important tool for the food engineers to reduce the hurdles of experimentation. Drying of food is a multi-physics phenomenon such as coupled heat and mass transfer. Moreover, food structure is multi-scale in nature, and the microstructural features play a great role in the food processing specially in drying. Previously simple macroscopic model was used to describe the drying phenomena which can give a little description about the smaller scale. The multiscale modeling technique can handle all the phenomena that occur during drying. In this special kind of modeling approach, the single scale models from bigger to smaller scales are interconnected. With the help of multiscale modeling framework, the transport process associated with drying can be studied on a smaller scale and the resulting information can be transferred to the bigger scale. This article is devoted to discussing the state of the art multi-scale modeling, its prospect and challenges in the field of drying technology. This article has also given some directions to how to overcome the challenges for successful implementation of multi-scale modeling.

Shrinkage of Food Materials During Drying: Current Status and Challenges.

The structural heterogeneities of fruits and vegetables intensify the complexity to comprehend the interrelated physicochemical changes that occur during drying. Shrinkage of food materials during drying is a common physical phenomenon which affects the textural quality and taste of the dried product. The shrinkage of food material depends on many factors including material characteristics, microstructure, mechanical properties, and process conditions. Understanding the effect of these influencing factors on deformation of fruits and vegetables during drying is crucial to obtain better-quality product. The majority of the previous studies regarding shrinkage are either experimental or empirical; however, such studies cannot provide a realistic understanding of the physical phenomena behind the material shrinkage. In contrast, theoretical modeling can provide better insights into the shrinkage that accompanies simultaneous heat and mass transfer during drying. However, limited studies have been conducted on the theoretical modeling of shrinkage of fruits and vegetables. Therefore, the main aim of this paper is to critically review the existing theoretical shrinkage models and present a framework for a theoretical model for the shrinkage mechanism. This paper also describes the effect of different drying conditions on material shrinkage. Discussions on how the diverse characteristics of fruits and vegetables affect shrinkage propagation is presented. Moreover, a comprehensive review of formulation techniques of shrinking models and their results are also presented. Finally, the challenges in developing a physics-based shrinkage model are discussed.

Multiscale Modeling for Food Drying: State of the Art.

Plant-based food materials are mostly porous in nature and heterogeneous in structure with huge diversity in cellular orientation. Different cellular environments of plant-based food materials, such as intercellular, intracellular, and cell wall environments, hold different proportions of water with different characteristics. Due to this structural heterogeneity, it is very difficult to understand the drying process and associated morphological changes during drying. Transport processes and morphological changes that take place during drying are mainly governed by the characteristics of and the changes in the cells. Therefore, to predict the actual heat and mass transfer process that occurs in the drying process and associated morphological changes, development of multiscale modeling is crucial. Multiscale modeling is a powerful approach with the ability to incorporate this cellular structural heterogeneity with microscale heat and mass transfer during drying. However, due to the huge complexity involved in developing such a model for plant-based food materials, the studies regarding this issue are very limited. Therefore, we aim in this article to develop a critical conceptual understanding of multiscale modeling frameworks for heterogeneous food materials through an extensive literature review. We present a critical review on the multiscale model formulation and solution techniques with their spatial and temporal coupling options. Food structure, scale definition, and the current status of multiscale modeling are also presented, along with other key factors that are critical to understanding and developing an accurate multiscale framework. We conclude by presenting the main challenges for developing an accurate multiscale modeling framework for food drying.

Food structure: Its formation and relationships with other properties.

Food materials are complex in nature as it has heterogeneous, amorphous, hygroscopic and porous properties. During processing, microstructure of food materials changes which significantly affects other properties of food. An appropriate understanding of the microstructure of the raw food material and its evolution during processing is critical in order to understand and accurately describe dehydration processes and quality anticipation. This review critically assesses the factors that influence the modification of microstructure in the course of drying of fruits and vegetables. The effect of simultaneous heat and mass transfer on microstructure in various drying methods is investigated. Effects of changes in microstructure on other functional properties of dried foods are discussed. After an extensive review of the literature, it is found that development of food structure significantly depends on fresh food properties and process parameters. Also, modification of microstructure influences the other properties of final product. An enhanced understanding of the relationships between food microstructure, drying process parameters and final product quality will facilitate the energy efficient optimum design of the food processor in order to achieve high-quality food.

Outcome of Endoscopic Sinus Surgery in the Treatment of Chronic Rhinosinusitis.

This prospective study was conducted to compare the outcome of endoscopic sinus surgery (ESS) using SNOT-20 score chart (subjective) and Lund & Kennedy scoring chart (objective) and carried out in the Department of Otolaryngology & Head-Neck Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Dhaka Medical College Hospital (DMCH) & Shaheed Suhrawardy Medical College Hospital (ShSMCH) from July 2010 to March 2012. Total 73 admitted cases were selected purposively for ESS, male 53(72.60%) and female 20(27.40%). Among the study participants 10(13.7%) had chronic rhinosinusitis with bilateral polyposis and 26(35.62%) had chronic rhinosinusitis with unilateral polyposis and 12(16.44%) had bilateral chronic rhinosinusitis without polyposis and 25(34.25%) had unilateral chronic rhinosinusitis without polyposis. Surgical procedures done among the patients were Uncinectomy (infundibulectomy), Middle Meatal Antrostomy; Anterior Ethmoidectomy; Sphenoidotomy, Associated septoplasty and no significant per or post operative complications were noted. In Chronic rhinosinusitis (CRS) with polyposis pre operative SNOT-20 mean and SD 1.322±0.341 and post ESS snot-20 mean and SD 0.3472±0.0755, CRS without polyposis pre operative SNOT-20 mean and SD 0.9297±0.86 and post ESS SNOT-20 mean and SD 1986±0.0558. In CRS with polyposis pre operative Lund & Kennedy score of endoscopic assessment, mean and SD 5.333±2.255 and post ESS mean and SD 1.31±1.009. In CRS without polyposis pre op Lund & Kennedy score mean and SD 3.108±1.074 and post ESS mean and SD 0.76±0.641.Post ESS SNOT-20 in CRS with Polyposis, 't' test result was 27.58 which was significant (p<0.001) and in CRS without Polyposis was 21.622 which was significant (p<0.001); Lund & Kennedy Score of post ESS in CRS with Polyposis 't' test result was 7.763 which was significant (p<0.001), CRS without Polyposis was 7.177 which was significant (p<0.001).This implies that outcome of ESS in treatment of CRS with or without polyposis had statistically significant role. Symptomatic relief and quality of life improvement after ESS was compared by improvement in post operative scores of SNOT-20 & Lund-Kennedy score of endoscopic assessment. Post operative lower values were considered to be better improvement status. The results of the study suggests that ESS performed in Chronic Rhinosinusitis without Polyposis cases, relief of symptoms and quality of life improved was better than Chronic Rhinosinusitis with Polyposis cases postoperatively as compared by SNOT-20 and Lund & Kennedy score of endoscopic assessment.

Complications of neck dissection at a tertiary level hospital: study of 30 cases.

Metastatic dissemination into lymph nodes of neck occurs frequently in head neck cancers which down grade the patient's curability and survival. Neck dissection is a curable option for its management. To evaluate the complications following different types of neck dissection. This cross sectional study was conducted among patients undergone different types of neck dissection due to cervical nodal metastasis and attended follow up during July 2010 to June 2011 in Department of ENTs and Head-Neck surgery Dhaka Medical College Hospital, Dhaka, Bangladesh. Among 30 selected patient, 23 were male (76.67%) and 7 were female (23.33%), age ranged from 31-72 years (Mean=59.1±5.44). In different modalities of neck dissection 11 were modified neck dissection (36.67%) and 10(33.33%) were radical neck dissection. Common indication was carcinoma of unknown origin (66.67%). Involved neck nodes were commonly level II-IV (69.99%). Nodal stage was N2(50%) and N3 (40%).Common immediate complications were bleeding 03(10%), facial oedema 02 (6.67%) and thoracic duct injury 02(6.67%). Intermediate complications were seroma 05(16.67%), wound infection 04(13.33%) and chylous fistula 02(6.67%), Late Complications were hypertrophic scar 07(23.33%) and shoulder syndrome 06(20%). Proper indications, skilled surgery along with early recognize and treatment in both early and late manifestations of neck dissection preventing its grave sequence.

Complications of endonasal endoscopic sinus surgery for management of nasal polyp and chronic sinusitis.

Sinusitis is defined as a condition manifested by inflammation of the mucous membrane of the nose & paranasal sinuses, fluid within this cavities and or underlying bone. Chronic rhinosinusitis is diagnosed by the presence of two or more of the following factors facial congestion/fullness, nasal obstruction, nasal discharge or discolored post nasal drainage, hyposmia/anosmia or one major and two of the following minor factors, headache. Halitosis, fatigue, dental pain, cough, ear pressure, fullness. The use of endoscope during surgery of nose & para nasal sinuses improves visualization enable greater preservation of normal structures and reduces the necessity for wide exposure. This cross-sectional study on 50 cases of chronic rhinosinusitis carried out during a period of 6 months. All the cases of both endonasal endoscopic sinus surgery (EESS) group and conventional group assessed clinically endoscopicaly and by imaging both pre and post-operative period. Twenty five cases were EESS group. Twenty five cases of conventional group. Follow-up frequencies are 1st week, 2nd week, 3rd week, 1st month, 3rd months, 6th months. In both type majority of patients in between 21-40 years, most of the cases were male, majority of patients present with headache (80)%, nasal discharge (70%), nasal obstruction (62%), major indication incase of EESS group were ethmoidal polyp 52% & conventional surgery group were chronic sinusitis (56%). Commonest complications were cheek swelling 10(40%) incase of conventional group, crusting 12(84%) in EESS group. Complete recovery incase of EESS were in 21(84%) cases and conventional surgery group 16(64%). Endonasal endoscopic sinus surgery has provided a safe & efficient method for dealing with different sinonasal diseases.

Mutations in the TRKA/NGF receptor gene in patients with congenital insensitivity to pain with anhidrosis.

Congenital insensitivity to pain with anhidrosis (CIPA; MIM 256800) is an autosomal-recessive disorder characterized by recurrent episodes of unexplained fever, anhidrosis (absence of sweating) and absence of reaction to noxious stimuli, self-mutilating behaviour and mental retardation. The genetic basis for CIPA is unknown. Nerve growth factor (NGF) induces neurite outgrowth and promotes survival of embryonic sensory and sympathetic neurons. Mice lacking the gene for TrkA, a receptor tyrosine kinase for NGF, share dramatic phenotypic features of CIPA, including loss of responses to painful stimuli, although anhidrosis is not apparent in these animals. We therefore considered the human TRKA homologue as a candidate for the CIPA gene. The mRNA and genomic DNA encoding TRKA were analysed in three unrelated CIPA patients who had consanguineous parents. We detected a deletion-, splice- and missense-mutation in the tyrosine kinase domain in these three patients. Our findings strongly suggest that defects in TRKA cause CIPA and that the NGF-TRKA system has a crucial role in the development and function of the nociceptive reception as well as establishment of thermoregulation via sweating in humans. These results also implicate genes encoding other TRK and neurotrophin family members as candidates for developmental defect(s) of the nervous system.

Identification and mutation analysis of the complete gene for Chediak-Higashi syndrome.

Chediak-Higashi syndrome (CHS) is a rare, autosomal recessive disorder characterized by hypopigmentation, severe immunologic deficiency with neutropenia and lack of natural killer (NK) cells, a bleeding tendency and neurologic abnormalities. Most patients die in childhood. The CHS hallmark is the occurrence of giant inclusion bodies and organelles in a variety of cell types, and protein sorting defects into these organelles. Similar abnormalities occur in the beige mouse, the proposed model for human CHS. Two groups have recently reported the identification of the beige gene, however the two cDNAs were not at all similar. Here we describe the sequence of a human cDNA homologous to mouse beige, identify pathologic mutations and clarify the discrepancies of the previous reports. Analysis of the CHS polypeptide demonstrates that its modular architecture is similar to the yeast vacuolar sorting protein, VPS15.

Impact of metabolic syndrome in acute myocardial infarction at hospital.

The study was aimed to find out the impact of metabolic syndrome in patients with acute myocardial infarction during hospital stay. This prospective study was carried out in coronary care unit, Mymensingh Medical College Hospital from August 2009 to May 2010. Patients were followed up for minimum 3 days to maximum 6 days after admission. Variables of this study were age, sex, smoking, anterior AMI, inferior AMI, Non STEMI, hyperglycemia, low high density lipoprotein (HDL), raised blood pressure, high triglyceride (TG), waist circumference, recurrent non fatal MI, heart failure (Killip class), arrhythmia (VT, VF), ejection fraction (EF), family history of cardiovascular (CV) risk factors. Considering inclusion and exclusion criteria total 100 patients were included and divided into two groups, Group A - Acute Myocardial Infarction (AMI) with Metabolic Syndrome (MS) and Group B - Acute Myocardial Infarction (AMI) without Metabolic Syndrome (MS). Investigations included ECG, FBS, fasting lipid profile, cardiac enzyme (troponin I) and echocardiography (2D & M mode). The data were analyzed by computer software SPSS version 12. Chi-square test, t test, ANOVA test was used as test of significance. Among the study population (n=100), female were 12.0%. Mean age of study population was 53.3±10.6 years vs. 47.5±11.3 years. Distribution of metabolic syndrome components in study population, High TG (?150mg/dl) was more prevalent (81.1% vs. 25.8%). Heart failure (Killip class) was significantly more in metabolic syndrome patients than those without metabolic syndrome (46.0 % vs. 20%). LV ejection fraction also lowers in metabolic syndrome patients (46.76±8.34 vs. 50.45±7.50) with MI. Among the components of metabolic syndrome, hyperglycemia had strongest association for development of heart failure (OR 3.05; 95% CI 0.80-12.14).

Enhancement of electrokinetic decontamination with EDTA.

The effect of ethylenediaminetetraacetic acid (EDTA) during electrokinetic decontamination (EKD) was investigated in this research. EDTA is a ligand that can form soluble complexes with precipitated heavy metals inside soil pores. Millpond sludge, primarily contaminated with lead (Pb) and zinc (Zn), was subjected to EKD with and without the presence of EDTA. Dilute EDTA solutions with strengths of 0.05 M and 0.125 M were injected into the millpond sludge by electroosmosis. Several beneficial effects of using EDTA were observed in this research. One was that the presence of EDTA substantially increased the electroosmotic (EO) flow in the millpond sludge indicating that it could significantly reduce the duration of EKD. Another advantage was that a significantly higher percentage of Pb and Zn removal was achieved from the solid phase due to the complexation of EDTA with these heavy metals. Also, EDTA was able to prevent the precipitation of metals at the cathode electrode, typically observed in EKD process.

Difficulty in diagnosis of nasopharyngeal carcinoma.

Due to difficult anatomical position nasopharyngeal carcinoma (NPC) is always challenging problems both from the diagnostic and therapeutic corner. A 24 years old lady came to our Department of Otolaryngology and Head-Neck Surgery with the complaints of epistaxis, right sided neck swelling, nasal obstruction and headache. On digital palpation Nasopharyngeal mass was found. We took biopsy from nasopharynx under indirect vision but report was not conclusive. Then we did CT scan, nasendoscopy. Nasendoscopy showed bilateral ethmoidal polyp with nasopharyngeal mass. We took biopsy from the nasopharyngeal mass and confirmed the diagnosis.

A Comprehensive, FAIR File Format for Neuroanatomical Structure Modeling.

With advances in microscopy and computer science, the technique of digitally reconstructing, modeling, and quantifying microscopic anatomies has become central to many fields of biological research. MBF Bioscience has chosen to openly document their digital reconstruction file format, the Neuromorphological File Specification, available at www.mbfbioscience.com/filespecification (Angstman et al., 2020). The format, created and maintained by MBF Bioscience, is broadly utilized by the neuroscience community. The data format's structure and capabilities have evolved since its inception, with modifications made to keep pace with advancements in microscopy and the scientific questions raised by worldwide experts in the field. More recent modifications to the neuromorphological file format ensure it abides by the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles promoted by the International Neuroinformatics Coordinating Facility (INCF; Wilkinson et al., Scientific Data, 3, 160018,, 2016). The incorporated metadata make it easy to identify and repurpose these data types for downstream applications and investigation. This publication describes key elements of the file format and details their relevant structural advantages in an effort to encourage the reuse of these rich data files for alternative analysis or reproduction of derived conclusions.