A review of refrigerant maldistribution

In recent years, conservation of energy has become a challenging issue in air-conditioning applications. In order to overcome this issue, many researchers have recommended the use of a Parallel Flow Condenser and a low Global Warming Potential and Ozone Depletion Potential refrigerant, such as R32, in air conditioning systems. However, PFC faces the critical challenge of flow maldistribution in the tubes. This literature review mainly examines the refrigerant maldistribution problem which has been investigated by previous researchers. It was found that many of the researchers did not properly analyse the influence of flow maldistribution profiles on the performance degradation of heat exchangers. In order to have a comprehensive analysis of tube-side maldistribution in Parallel Flow microchannel heat exchangers, it is recommended that the influence of the higher statistical moments of the probability density function of the flow maldistribution profiles on performance degradation be quantified. Additionally, R32 maldistribution should be analysed and compared with R410A, which is the current commonly used refrigerant in air conditioning units. Moreover, in order to have a realistic simulation of the effect of refrigerant flow maldistribution profiles on performance degradation of heat exchangers, the effect of superheat and sub-cooling must be analysed

Candida lipolytica candidemia as a rare infectious complication of acute pancreatitis: A case report and literature review

Candida lipolytica candidemia is a rare but an emerging pathogenic yeast infection in humans. It can gain access to the bloodstream through intravascular catheterization, especially through central venous catheters in immunocompromised or critically ill patients during hospitalization. In this report, we present a noncatheter-related C. lipolytica candidemia infection in an 84-year-old man who was admitted due to acute pancreatitis. The possible pathogenesis and management of C. lipolytica candidemia are highlighted. It was an unusual infectious complication of acute pancreatitis. Clinicians should be aware that such an opportunistic pathogen can lead to invasive candidemia infection. In clinical practice, systemic antifungal therapy and the removal of the potentially infected central venous catheter might be recommended for the treatment of C. lipolytica candidemia

Shikonin enhances efficacy of a gene-based cancer vaccine via induction of RANTES

<p>Abstract</p> <p>Background</p> <p>Shikonin, a phytochemical purified from <it>Lithospermum erythrorhizon</it>, has been shown to confer diverse pharmacological activities, including accelerating granuloma formation, wound healing, anti-inflammation and others, and is explored for immune-modifier activities for vaccination in this study. Transdermal gene-based vaccine is an attractive approach for delivery of DNA transgenes encoding specific tumor antigens to host skin tissues. Skin dendritic cells (DCs), a potent antigen-presenting cell type, is known to play a critical role in transmitting and orchestrating tumor antigen-specific immunities against cancers. The present study hence employs these various components for experimentation.</p> <p>Method</p> <p>The mRNA and protein expression of RANTES were detected by RT-PCR and ELISA, respectively. The regional expression of RANTES and tissue damage in test skin were evaluated via immunohistochemistry assay. Fluorescein isothiocyanate sensitization assay was performed to trace the trafficking of DCs from the skin vaccination site to draining lymph nodes. Adjuvantic effect of shikonin on gene gun-delivered human gp100 (hgp100) DNA cancer vaccine was studied in a human gp100-transfected B16 (B16/hgp100) tumor model.</p> <p>Results</p> <p>Among various phytochemicals tested, shikonin induced the highest level of expression of RANTES in normal skin tissues. In comparison, mouse RANTES cDNA gene transfection induced a higher level of mRANTES expression for a longer period, but caused more extensive skin damage. Topical application of shikonin onto the immunization site before gene gun-mediated vaccination augmented the population of skin DCs migrating into the draining lymph nodes. A hgp100 cDNA gene vaccination regimen with shikonin pretreatment as an adjuvant in a B16/hgp100 tumor model increased cytotoxic T lymphocyte activities in splenocytes and lymph node cells on target tumor cells.</p> <p>Conclusion</p> <p>Together, our findings suggest that shikonin can effectively enhance anti-tumor potency of a gene-based cancer vaccine via the induction of RANTES expression at the skin immunization site.</p

The influence of refrigerant (R32) flow maldistribution on the thermal performance of a microchannel heat exchanger without considering superheat and sub-cool / Chng Ming Hui, Chin Wai Meng and Tang Sai Hong

The research work reported in this paper investigates the numerical study on the influence of statistical moments of probability density function of R32 tube-side flow maldistribution on the thermal performance of microchannel heat exchanger. A model without considering superheat and sub-cool was developed to analyze the effect of mean, standard deviation and skew of the refrigerant maldistribution profile on the heating capacity degradation of the heat exchanger. Next, the performance degradation of microchannel heat exchanger due to refrigerant (R32) maldistribution was quantified and analyzed. After that, the model was validated by doing experiment. Finally, a performance deterioration correlation related to refrigerant maldistribution without considering superheat and sub-cool was developed to offer a faster and simpler method to analyze the maldistribution problem. It is found that mean and standard deviation have the highest impact on the performance deterioration. Maldistribution with high standard deviation and high negative skew gives a large magnitude of performance deterioration. For standard deviation more than 0.3, the deterioration can up to 1%. Besides that, the deterioration reaches 1% for skew below -0.5. Furthermore, the deterioration is as high as 4% when the mean is less than 0.9. Hence, the first three moments such as mean, standard deviation and skew should be optimized in the effort of improve the thermal performance of the heat exchanger. The proposed correlation in this work offers a faster and simpler method for a quick estimate of the degradation factor

Highly porous chitosan beads embedded with silver-graphene oxide nanocomposites for antibacterial application

Incorporation of silver nanomaterial into polymer matrix can further accomplished their potential usage in real life applications. In our previous study, silver nanoparticles (AgNPs) and silver-graphene oxide nanocomposites (AgGO) were prepared via a rapid microwave-assisted method. Hereby, the as-synthesized AgNPs or AgGO was dispersed in a chitosan solution. Subsequently, the resultant mixture solution was further coagulated in a coagulation bath containing sodium hydroxide via a neutralization process. This resulted in the formation of spherical-shaped chitosan beads. The structure of the beads showed that the chitosan beads embedded with AgGO exhibited a more porous structure as compared to the plain chitosan beads. Furthermore, the chitosan beads containing AgNPs or AgGO were tested for their antibacterial activity against Escherichia coli and Staphylococcus aureus. The antibacterial results indicated that the silver nanomaterial contained chitosan beads could effectively inhibit the growth of both E. coli and S. aureus as compared to the bare chitosan beads. The produced chitosan nanocomposite envisioned that can be potentially employed for water disinfection purpose

A Research Protocol of Hands-On Healthy Meal Preparation Intervention (Kidchen Study) to Improve Children’s Nutritional Outcomes

The objective of this paper is to describe the protocol of a 12-week hands-on healthy meal preparation intervention among children, up to a 3-month follow-up. The aim of KidChen Study (kids in kitchen) is to improve children’s nutritional outcomes. In this randomized-controlled trial, simple random sampling will be used to select schools in Kuala Lumpur, Malaysia. Subsequently, the selected schools (n=2) will be assigned randomly to either the intervention or control group. The current study will include healthy Malaysian children aged 10–11 years old with no serious disease or food allergy. The intervention is based on Social Cognitive Theory that addresses personal and environmental factors for changing children’s behaviour. Children from the intervention group will receive a 60-minute home food environment module with their parents consisting of nutrition talk, healthy food tasting, parent-child quiz; and five 60 minute interactive hands-on healthy meal preparation modules focusing on core food groups coupled withstorytelling sessions to incorporate nutrition education. Outcome measures are children’s psychosocial factors towards healthy meal preparation (knowledge, attitude, practice, self-efficacy), dietary behaviour, food consumption pattern, home food availability and anthropometric measures (BMI-for-age z-score, body fat percentage, waist circumference). Repeated measures ANOVA will be used to evaluate the intervention outcomes. KidChen Study is an experiential learning approach to instil a positive attitude towards nutrition and empower children with nutrition skills. We anticipate that the intervention will advocate healthy eating behaviour among children, impacting their nutritional outcomes over time

Use of Rubber Dams During Root Canal Treatment in Taiwan

Background/PurposeIsolation of teeth with rubber dams is an important procedure for infection control in dentistry, especially in endodontic treatment. This study surveyed the prevalence of rubber dam usage in nonsurgical root canal treatment (RCT) by dentists under the National Health Insurance system in Taiwan.MethodsA total of 1,332 completed RCT cases were randomly selected from a large database from the Bureau of National Health Insurance in Taiwan in 2004. The radiographs and dental charts of the selected cases were evaluated for the prevalence of rubber dam usage in RCT. The frequencies of rubber dam usage for RCT by dentists were compared between hospitals and private dental clinics and among six different regions in Taiwan.ResultsThe overall prevalence of rubber dam usage for RCT by dentists under the National Health Insurance system in Taiwan was 16.5%. The frequency of rubber dam usage for RCT by dentists in hospitals (32.8%) was significantly higher than that (10.3%) in private dental clinics (p < 0.0001). However, there was no significant difference in the frequency of rubber dam usage for RCT by dentists among six different geographic regions in Taiwan.ConclusionThe prevalence of rubber dam usage for RCT by dentists in Taiwan is relatively low. Because rubber dam isolation of an endodontically-treated tooth can provide better infection control, increase patient protection, and improve treatment efficiency, there is an urgent need to advise dentists in Taiwan to use rubber dams for every RCT case

Cyclosporine A Eye Drop-Induced Elongated Eyelashes: A Case Report

Purpose: The most common ocular adverse event following the use of cyclosporine A (CsA) 0.05% ophthalmic emulsion is ocular burning (17%). Other adverse effects that have been reported include conjunctival hyperemia (1–5%), discharge, epiphora, eye pain, foreign body sensation, pruritus, stinging and blurred vision. Here, we report a specific side effect of CsA, namely eye drop-induced eyelash elongation in a patient with refractory giant papillary conjunctivitis. Design: Observational case report. Methods: Case report and review of the literature. Results: A 32-year-old female with giant papillary conjunctivitis on the left eye, who had undergone papillectomy 3 years previously and was refractory to topical steroid therapy, was treated with CsA 0.05% ophthalmic emulsion (Restasis) 4 times a day, preservative-free artificial tears and gentamicin ophthalmic solution in the left eye. After 5 months of topical CsA treatment, elongated eyelashes of her left eye were observed without other adverse effects. Conclusion: Although hypertrichosis and trichomegaly have been documented in the literature as side effects of systemic CsA, topical CsA 0.05% eye drop-induced elongated eyelashes have not been reported, and we believe ophthalmologists should be mindful and inform patients about this specific side effect

The Manhattan effect: When relationship commitment fails to promote support for partners’ interests

Research on close relationships has frequently contrasted one’s own interests with the interests of the partner or the relationship and has tended to view the partner’s and the relationship’s interests as inherently aligned. The present article demonstrated that relationship commitment typically causes people to support their partner’s personal interests but that this effect gets weaker to the extent that those interests misalign or even threaten the relationship. Studies 1a and 1b showed that (a) despite their strong correlation, partner-oriented and relationship-oriented concerns in goal-directed behaviors are separable and (b) relationship commitment strengthens only the link between relationship-oriented motivation and the goal pursuit (not the link between partner-oriented motivation and the goal pursuit). The remaining 7 studies zero in on circumstances in which the partner’s and the relationship’s interests are in conflict, demonstrating that (c) relationship commitment reliably increases the tendency to support the partner’s personal interests when those interests do not pose a strong threat to the relationship but that (d) this effect becomes weaker—and even reverses direction—as the relationship threat posed by the partner’s interests becomes stronger. The reduction or reversal of the positive link between relationship commitment and propartner behaviors in such situations is termed the Manhattan effect. These findings suggest that the partner-versus-relationship conflicts provide fertile ground for novel theorizing and empirical investigations and that relationship commitment appears to be less of a partner-promoting construct than relationship science has suggested; instead, its role appears to be focused on promoting the interests of the relationship

The Potential Utility of Curcumin in the Treatment of HER-2-Overexpressed Breast Cancer: An In Vitro and In Vivo Comparison Study with Herceptin

HER-2 is an important oncoprotein overexpressed in about 15–25% of breast cancers. We hypothesized that the ability of curcumin to downregulate HER-2 oncoprotein and inhibit the signal transduction pathway of PI3K/Akt, MAPK, and NF-κB activation may be important in the treatment of HER-2-overexpressed breast cancer. To examine the effect of curcumin on breast cancer cells, MCF-7, MDA-MB-231, MCF-10A, BT-474, and SK-BR-3-hr (a herceptin resistant strain from SK-BR-3) cells were used for in vitro analysis. The in vivo effect of curcumin on HER-2-overexpressed breast cancer was investigated with the HER-2-overexpressed BT-474 xenograft model. Cell growth, cell cycle change, the antimobility effect, signal transduction, and xenograft volume analysis between groups treated with herceptin and/or curcumin were tested. Curcumin decreased the cell growth of various breast cancer cell lines (MCF-7, MDA-MB-231, MCF-10A, BT-474, and SK-BR-3-hr). In Western blot analysis, the phosphorylation of Akt, MAPK, and expression of NF-κB were reduced in BT-474 cells, but not in SK-BR-3-hr cells, after treatment with herceptin. When treated with curcumin, the HER-2 oncoprotein, phosphorylation of Akt, MAPK and expression of NF-κB were decreased in both BT-474 and SK-BR-3-hr cells. In the BT-474 xenograft model, though not as much as herceptin, curcumin did effectively decrease the tumor size. The combination of curcumin with herceptin was not better than herceptin alone; however, the combination of taxol and curcumin had an antitumor effect comparable with taxol and herceptin. The results suggested that curcumin has potential as a treatment for HER-2-overexpressed breast cancer