1,354,574 research outputs found
A framework to support the design of a regenerative indoor environment
No full textIn recent decades, a new generation of “green indoor” spaces has fulfilled the latest regulations and guidelines for a carbon-neutral society. Their targets are reachable through certifications embracing sets of measures and the adverse effects on occupants. Notwithstanding this, it has constituted a significant step forward in building design. However, the challenges given by climate change and the ecological crises lead to the need for new disruptive approaches to indoor design and function, enhancing human health and adopting regenerative design” at the forefront of buildings’ conception. Besides the positive energyperformance attributes, the creation of a Regenerative Indoor Environment utilizes appropriate construction technologies and systems, to reinforce human
health, and enhance users’ experience. This regenerative paradigm shift foresees putting ecosystems at the centre and the users’ psycho-physiological wellbeing, thus magnifying their collaboration. Despite regenerative design gaining some attention, a framework towards its implementation promoting the actual performances of the indoor environment is still missing, and designers do navigate among guidelines with no apparent performance indicators to be achieved, technologies to be implemented, or methodologies for postoccupancy evaluations. These three levels, constituting a stepwise methodology, are addressed by the authors within the sections of this paper, and validated as an example of the office buildings’ typology. i) What characterizes a Regenerative Indoor Environment? ii) What technical solutions underpin the realization of a Regenerative Indoor Environment? iii) What methods or standards are crucial for its evaluation? With these premises, the paper contributes to supporting the creation of a regenerative indoor’ design, by sampling and outlining regenerative indoor performances to be obtained, describing the adequate tools to implement them, as well as by displaying approaches and solutions for their final verification
Protein, peptide and non-peptide drug PEGylation for therapeutical application: a review
No full textFor many years proteins have been investigated as therapeutic agents, but unfortunately their potential advantages could not be exploited completely. The main drawbacks regard the intrinsic short life in the body, the immunological adverse reaction and the proteolytic digestion. Among all the approaches studied for overcoming these problems, PEGylation (the modification of molecules with polyethylene-glycol, PEG) achieved the most interesting results leading to a novel series of products that reached already the market and, furthermore, promising others will be available soon. Since the first studies in this field, the conjugation of PEG to a protein showed the possibility to improve the pharmacokinetics profile of linked drug. In the last years this technology, firstly developed for proteins, has been transferred to non-peptide drugs, opening a new area of investigation that is now receiving increasing interest. This leads to new opportunities for many therapeutic treatments since it is possible to use molecules that could not be used before for limitations such as inadequate water solubility, high non-specific toxicity and poor pharmacokinetic profiles. In this review the recent achievements in PEGylation of protein, peptide and non-peptide drugs were described for what the chemistry of binding is concerned, and many examples from literature are reported both in the field of protein therapeutic as well as non-peptide drugs
Karakteristik Arus Pasut Di Perairan Teluk Amurang Menggunakan Pemodelan Numerik
No full textTeluk Amurang, Sulawesi Utara, memiliki sistem arus pasut yang kompleks akibat pengaruh faktor geografis dan oseanografi. Studi sebelumnya telah menganalisis pengaruh pasang surut terhadap pola arus serta karakteristik arus berdasarkan periode umur bulan, namun belum secara spesifik membahas pola pergerakan arus pasut dengan resolusi spasial dan temporal yang lebih tinggi. Oleh karena itu, penelitian ini bertujuan untuk memodelkan dan menganalisis pola arus pasut di Teluk Amurang menggunakan pendekatan numerik dengan validasi yang lebih ketat. Pemodelan numerik dilakukan menggunakan perangkat lunak MIKE 21 dengan modul hidrodinamika (HD). Proses ini mencakup pengumpulan data batimetri, pasang surut, serta pengaturan batas domain. Model yang dihasilkan divalidasi menggunakan nilai Root Mean Square Error (RMSE) untuk memastikan tingkat akurasi hasil simulasi. Validasi model menunjukkan RMSE sebesar 8,1% (stasiun 1), 10% (stasiun 2), dan 8% (stasiun 3), yang masih dalam batas penerimaan (RMSE <40%). Hasil simulasi menunjukkan bahwa arus dominan berasal dari barat dengan kecepatan maksimum 1,37 m/s di stasiun 2 dan 1,2 m/s di stasiun 3, sebelum berbelok ke utara dan barat laut. Arus di stasiun 1 lebih lemah (0,0029–0,017 m/s) karena lokasi yang lebih terlindungi dalam teluk. Dibandingkan studi sebelumnya, penelitian ini menggunakan resolusi spasial dan temporal yang lebih tinggi serta validasi model yang lebih ketat untuk meningkatkan akurasi prediksi pola arus pasut. Hasil penelitian ini memberikan informasi penting bagi keselamatan navigasi, perencanaan pembangunan pesisir, dan analisis transport sedimen di Teluk Amurang
HEATED AND COOLED CHAIR APPARATUS
No full textArticles of furniture with a system of heating and cooling that can be integrated into a building environmental control net work are provided. The heating/cooling system of the article has surfaces of a porous or non-porous, moisture-permeable material allowing convective and evaporative heat exchange from the body surface to the environment. The material covers a plenum that has reflective Surfaces to reduce radiant losses and low-wattage fans to circulate air that convectively cools the occupant. Resistance heating may be incorporated at key occupant contact areas in the seat and backrest. Temperature, occupancy and other sensors can be incorporated. A control interface controls the actions of the heating/cooling system of the article and can interact with a network server to transmit measurements of environmental temperatures and occupant selection of control settings that are useful for control of the buildings indoor environment
The Use of Ceiling Fans in Reverse-Flow Mode for Comfort Cooling: Physiological Aspects and Relationship with International Standards
No full textIn a warming planet, the energy demand for space cooling is constantly increasing. Air movement can be considered an energy efficient mean to provide thermal comfort in warm season. Ceiling fans are among the most adopted sources of air movement in buildings, and they are widely used in many countries. In warm environmental conditions, ceiling fans usually blow air from the ceiling to the occupants. While the heat generated from a human body does not vary, this forced convection accelerates the heat transfer between the parts of the body skin hit by the air flow and the surrounding thermal environment. The elevated air speed increases the convective heat transfer coefficients and the rate of evaporation from those parts of the skin. In cold seasons, ceiling fans are often used in reverse-flow mode for destratification purposes. In this case, the air speed is usually much lower than the direct flow, but considerably more uniform in the room. Some manufacturing companies lately raised their interest in analyzing the reverse-flow as a means to provide thermal comfort also in summer, providing a gentler airflow that might be less likely to cause draft for the users. Hence, the aim of this study is to investigate the extent to which the reverse-flow could be used also for cooling in warm conditions. CFD simulations were used to evaluate (i) the air speed field generated using direct and reverse flow (magnitude and spatial distribution), and (ii) how the heat transfer coefficients on the different body parts vary in both cases. The former enables to provide thermo-physiological insights, while the latter a comparison with air speed values reported in standards such as ASHRAE55. The results indicate that, although more evenly distributed within the room, the generated air speed with the reverse flow is considerably low. Hence, from a physiological point of view, it would not be sufficient to provide comfort cooling. Further work with human participants will investigate whether this low speed might generate a subjective perception of comfort cooling
State of the art in PEGylation: The great versatility achieved after forty years of research
No full textIn the recent years, protein PEGylation has become an established and highly refined technology by moving forward from initial simple random coupling approaches based on conjugation at the level of lysine ε-amino group. Nevertheless, amino PEGylation is still yielding important conjugates, currently in clinical practice, where the degree of homogeneity was improved by optimizing the reaction conditions and implementing the purification processes. However, the current research is mainly focused on methods of site-selective PEGylation that allow the obtainment of a single isomer, thus highly increasing the degree of homogeneity and the preservation of bioactivity. Protein N-terminus and free cysteines were the first sites exploited for selective PEGylation but currently further positions can be addressed thanks to approaches like bridging PEGylation (disulphide bridges), enzymatic PEGylation (glutamines and C-terminus) and glycoPEGylation (sites of O- and N-glycosylation or the glycans of a glycoprotein). Furthermore, by combining the tools of genetic engineering with specific PEGylation approaches, the polymer can be basically coupled at any position on the protein surface, owing to the substitution of a properly chosen amino acid in the sequence with a natural or unnatural amino acid bearing an orthogonal reactive group.
On the other hand, PEGylation has not achieved the same success in the delivery of small drugs, despite the large interest and several studies in this field. Targeted conjugates and PEGs for combination therapy might represent the promising answers for the so far unmet needs of PEG as carrier of small drugs.
This review presents a thorough panorama of recent advances in the field of PEGylation
Improvement of Drug Therapy by Covalent PEG Conjugation: An Overview From a Research Laboratory
No full textIn the last two decades, efforts focused in the field
of drug delivery have made it possible to reach important
goals, especially with proteins and peptides. The story of
the evolution of this matter is vast and it is difficult to summarize
its various aspects in a single review. On the other
hand, it could be really interesting to look at the inside story
of a typical academic research lab that has dedicated almost
all its resources to drug delivery. In our case, an initial interest
in the issue of protein conformation stability soon paved
the way for a new area of study: the modification of proteins
with synthetic polymers. We have seen this technique transformed
from a crude and inhomogeneous procedure into a
well-recognized and successful approach. This great advance
has been possible thanks to the development of dedicated
chemical coupling methods and to the better understanding
of the behavior of polymers in vivo. In particular,
among the several polymers investigated, PEG has became
the best polymer for protein modification. Exploiting the
unique properties of this polymer, we have conducted several
investigations in the field of protein PEGylation and then
transferred the acquired know-how to the development of
conjugates with low molecular weight drug. This last aspect
still presents several unmet needs that are awaiting proper
solutions
Pegylation of Biological Molecules and Potential Benefits: Pharmacological Properties of Certolizumab Pegol
No full textPEGylation of biological proteins, defined as the covalent conjugation of proteins with polyethylene glycol (PEG), leads to a number of biopharmaceutical improvements, including increased half-life, increased solubility and reduced aggregation, and reduced immunogenicity. Since their introduction in 1990, PEGylated proteins have significantly improved the management of various chronic diseases, including rheumatoid arthritis (RA) and Crohn's disease. Certolizumab pegol is the only PEGylated anti-tumour necrosis factor (TNF)-α agent. It is a PEGylated, humanised, antigen-binding fragment of an anti-TNF monoclonal antibody. Unlike other anti-TNF agents, it has no crystallisable fragment (Fc) domain. Because of its novel structure, certolizumab pegol may have a different mechanism of action to the other anti-TNF agents, and also has different pharmacodynamic properties, which could possibly translate to a different safety profile. Pharmacodynamic studies have shown that certolizumab pegol binds to TNF with a higher affinity than adalimumab and infliximab. Certolizumab pegol is also more potent at neutralising soluble TNF-mediated signalling than adalimumab and infliximab, and has similar or lesser potency to etanercept. Certolizumab pegol does not cause detrimental in vitro effects such as degranulation, loss of cell integrity, apoptosis, complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity. Certolizumab pegol may also penetrate more effectively into inflamed arthritic tissue than other anti-TNF agents, and is not actively transported across the placenta during pregnancy. Pharmacokinetic studies in healthy volunteers demonstrated that single intravenous and subcutaneous doses of certolizumab pegol had predictable pharmacokinetics. The pharmacokinetics of certolizumab pegol in patients with RA and Crohn's disease were consistent with pharmacokinetics in healthy volunteers
Modulation Techniques for Three-Phase Three-Level NPC Inverters: a Review and a Novel Solution for Switching Losses Reduction and Optimal Neutral-Point Balancing in Photovoltaic Applications
No full textA number of modulation strategies have been proposed in literature in the particular case of three-phase three-level NPC inverter, each one focusing on the optimization of specific aspects and performance of the converter. Nevertheless a comprehensive analysis of state-of-art techniques and their specific features suitable for a photovoltaic (PV) applications is still missing, such a study being highly desirable.
Both carrier-based and space vector modulation techniques are analyzed in this paper, highlighting specific features and limitations, especially related to PV applications. Basic issues are considered and compared among modulation strategies, namely: switching losses, low-frequency oscillations of the neutral-point (NP) voltage, total harmonic distortion (THD) and weighted total harmonic distortion (WTHD) of the phase currents and line voltages, dynamic response of the neutral-point voltage control loop under imbalance conditions and modulation algorithm complexity. A hybrid modulation strategy assisted by an optimal neutral-point voltage controller is then proposed aiming at both the reduction of the switching losses with a limited deterioration of the output voltage/current quality and fast dynamics control of the neutral point voltage. Those features allow the development of reduced dc bus capacitance PV inverters with optimized efficiency and quality of the output waveforms. Simulation and experimental results based on a TMS320F28069 DSP controller and a PV inverter are presented to confirm the effectiveness of the proposal
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