A Coding Variant in TMC8 (EVER2) Is Associated with High Risk HPV Infection and Head and Neck Cancer Risk

HPV infection is a causal agent in many epithelial cancers, yet our understanding of genetic susceptibility to HPV infection and resultant cancer risk is limited. Epidermodysplasia Verruciformis is a rare condition of extreme susceptibility to cutaneous HPV infection primarily attributable to mutations in TMC6 and TMC8. Genetic variation in the TMC6/TMC8 region has been linked to beta-type HPV infection and squamous cell carcinoma of the skin, cervical cancer, HPV persistence and progression to cervical cancer. Here, we have tested the hypothesis that the common TMC8 SNP rs7208422 is associated with high-risk HPV infection and risk of head and neck squamous cell carcinoma (HNSCC). Seropositivity to the HPV L1 protein (HPV16, 18, 11, 31, 33, 35, 45, 52, 58) was measured in 514 cases and 452 population-based controls. Genotype was significantly associated with seropositivity to HPV18 L1 (OR TT vs AA = 0.48, 95% CI = 0.22–0.99) and borderline significantly associated with HPV16 L1 (OR TT vs AA = 0.58, 95% CI = 0.22–1.17). There was a consistent inverse association between TMC8 genotype and infection with other HPV types, including statistically significant associations for HPV31 and HPV52. Consistent with these results, the variant T genotype was associated with a reduced risk of HNSCC (ORAT: 0.63, 95% CI 0.45–0.89, ORTT: 0.54, 95% CI 0.36–0.81), even among subjects seronegative for all HPV types (ORAT: 0.71, 95% CI 0.45–1.11, ORTT: 0.54, 95% CI 0.31–0.93). Our data indicate that common genetic variation in TMC8 is associated with high-risk HPV infection and HNSCC etiology

“Performance Comparison of a Heating Tower Heat Pump and an Air-Source Heat Pump: A Comprehensive Modeling and Simulation Study

The heating tower heat pump (HTHP) is proposed as an alternative to the conventional air-source heat pump (ASHP). To investigate the performance improvements of the HTHP over the ASHP, a comprehensive comparison between the two systems was carried out based on a simulation study. Physics-based models for the ASHP and HTHP were developed. The performance of the ASHP under frosting conditions was corrected with a newly developed frosting map, and the regeneration penalization was considered for the HTHP. Based on the models and corrections, hourly simulations were carried out in an office building in Nanjing, China. The results show that the average energy efficiency of the HTHP in summer is 23.1% higher than that of the ASHP due to the water-cooled approach adopted by the HTHP. In winter, the HTHP achieves an increase of 7.4% in efficiency due to the frost free and energy storage characteristics. While the initial cost of the HTHP is 1.2% higher than that of the ASHP, the HTHP can still save 9.7% cost in a 10-year period because of its lower power consumption.</p

Model-based optimal operation of heating tower heat pump systems

In current applications of heating tower heat pumps (HTHPs), the systems tend to run with constant speed or fixed set points, which can be inefficient under varying weather data and building loads. To address this issue, this study proposes a model-based optimal operation of the HTHPs to achieve energy savings in both cooling and heating modes. Firstly, a physics-based model for an existing HTHP system was developed. Then, artificial neural network (ANN) models were developed and trained with vast amount of operational data generated by the physics-based model. The ANN models were found to be highly accurate (average relative error less than 1%) and computationally efficient (about 300 times faster than the physics-based model). After that, three optimal approaches were proposed to minimize the total energy consumption of the HTHP system. Approach 1 optimizes the load distribution between different heat pump units. Approach 2 optimizes the speed of fans and pumps by fixed approach and range of the condenser water (or evaporator solution). Approach 3 optimizes both the load distribution and the speed of fans and pumps. The optimization is implemented by using the ANN models, proposed approaches, and a genetic algorithm via a case study. The results show that the energy savings in the cooling season are 2.7%, 11.4%, and 14.8% by the three approaches, respectively. In the heating season, the energy savings of the three approaches are 1.6%, &minus;1.4%, and 4.7%, respectively. Moreover, the thermodynamic performance in typical days was analyzed to investigate how energy savings could be achieved. </div

A novel PCR-based method for high throughput prokaryotic expression of antimicrobial peptide genes

<p>Abstract</p> <p>Background</p> <p>To facilitate the screening of large quantities of new antimicrobial peptides (AMPs), we describe a cost-effective method for high throughput prokaryotic expression of AMPs. EDDIE, an autoproteolytic mutant of the N-terminal autoprotease, Npro, from classical swine fever virus, was selected as a fusion protein partner. The expression system was used for high-level expression of six antimicrobial peptides with different sizes: Bombinin-like peptide 7, Temporin G, hexapeptide, Combi-1, human Histatin 9, and human Histatin 6. These expressed AMPs were purified and evaluated for antimicrobial activity.</p> <p>Results</p> <p>Two or four primers were used to synthesize each AMP gene in a single step PCR. Each synthetic gene was then cloned into the pET30a/His-EDDIE-GFP vector via an <it>in vivo </it>recombination strategy. Each AMP was then expressed as an Npro fusion protein in <it>Escherichia coli</it>. The expressed fusion proteins existed as inclusion bodies in the cytoplasm and the expression levels of the six AMPs reached up to 40% of the total cell protein content. On <it>in vitro </it>refolding, the fusion AMPs was released from the C-terminal end of the autoprotease by self-cleavage, leaving AMPs with an authentic N terminus. The released fusion partner was easily purified by Ni-NTA chromatography. All recombinant AMPs displayed expected antimicrobial activity against <it>E. coli</it>, <it>Micrococcus </it>luteus and <it>S. cerevisia</it>.</p> <p>Conclusions</p> <p>The method described in this report allows the fast synthesis of genes that are optimized for over-expression in <it>E. coli </it>and for the production of sufficiently large amounts of peptides for functional and structural characterization. The Npro partner system, without the need for chemical or enzymatic removal of the fusion tag, is a low-cost, efficient way of producing AMPs for characterization. The cloning method, combined with bioinformatic analyses from genome and EST sequence data, will also be useful for screening new AMPs. Plasmid pET30a/His-EDDIE-GFP also provides green/white colony selection for high-throughput recombinant AMP cloning.</p

Feasibility Study on Entransy Analysis Applied in the Operation Optimization of Air Conditioning Systems

To optimize the operation of air conditioning systems, the extremum entransy increase principle is proposed, and an entransy loss model for each component and entransy increase model for the whole system are established for air conditioning systems based on entransy theory. The entransy increase rate of the air conditioning system under different operation conditions is experimentally studied when the system cooling load and total power consumption are fixed separately. The results prove that the extremum entransy increase principle holds and determine the optimal operation conditions. When the system cooling load is 5 kW, the optimal compressor frequency is 70 Hz, optimal chilled water flow rate is 0.6 kg/s, and optimal cooling water flow rate is 0.9 kg/s. These parameter values produce the minimum system entransy increase rate, minimum power consumption rate, and maximum system efficiency. When the system power consumption is 2.8 kW, the optimal compressor frequency, chilled water flow rate, and cooling water flow rate are 97.9 Hz, 0.41 kg/s, and 1.00 kg/s, leading to the maximum system entransy increase rate, maximum system cooling load, and maximum system efficiency