The mobilization of stored lipid by hormones is a fundamental function of fat cells, and there is strong evidence that perilipin (Plin), a lipid droplet scaffold, and adipose tissue triglyceride ...lipase (Atgl), a triglyceride-specific lipase, play critical roles. Previous work suggested that Abhd5, a protein activator of Atgl, coordinates with Plin in controlling basal and stimulated lipolysis; however, the underlying mechanism is controversial. The present experiments investigated protein trafficking and interactions among Plin, Atgl, and Abhd5 in live cells. The results demonstrate that Plin binds Abhd5 with high affinity and thereby suppresses the interaction of Abhd5 with Atgl. Sequestration of Abhd5 appears to a major mechanism by which Plin reduces basal lipolysis. Phosphorylation of Plin on serine 492 or serine 517 rapidly releases Abhd5 from Plin, allowing Abhd5 to directly interact with Atgl. Imaging experiments demonstrated that the Plin-dependent interaction of Abhd5 and Atgl occurs mainly, but not exclusively, on lipid droplets that contain Plin.
Energy is the lifeblood of the modern world. Because of the negative environmental impacts and limited sources of fossil fuels, researchers are increasingly focusing on renewable energy sources, ...particularly solar energy due to its cleanliness and natural availability. Along with photovoltaic systems, solar thermal energy has been used over the last few decades to meet the refrigeration needs for both domestic and industrial purposes. This study presents a review of different solar thermal refrigeration systems, with a specific focus on solar absorption refrigeration systems and solar adsorption refrigeration systems within various working fluids. The different working pairs are illustrated by considering their coefficients of performance, specific cooling power, cooling capacity and minimum and maximum working temperatures. By considering cooling efficiency and other problems, such as swelling and agglomeration, the study also explores solar thermal hybrid cooling systems with heterogeneous composite pairs.
Global environmental concerns, increasing energy demands and developments in renewable energy technologies present a new possibility to implement renewable energy sources. Solar energy is the most ...prominent among renewable sources, as it is an inexhaustible resource and its exploitation has thus far been ecologically friendly. The potential amount of solar energy is considerably greater than current worldwide energy demands. Solar energy has been developing more rapidly than the other renewable energy sources for the last few decades. The best way to harvest the sun’s power is photovoltaic (PV) technology. This paper presents a study on solar energy in the form of a stand-alone and hybrid power generation system used to electrify off-grid locations. The stand-alone solar-PV system developed here is intended to be used to power a single house or a small community and it also functions as a mini-grid, generating power in places where adequate solar radiation is available throughout the year. However, many places throughout the world experience unsteady amounts of solar radiation and in those places, a hybrid solar-PV system is the most efficient solution for electrification. The main benefit of the hybrid system is that the weakness of one source is covered by the other source. This paper also presents some comparative case studies, project examples and demonstrations of stand-alone solar and hybrid solar systems implemented at various locations throughout the world over the last twelve years.
Microtubules are dynamic polymers built of tubulin dimers that attach in a head-to-tail fashion to form protofilaments, which further associate laterally to form a tube. Asynchronous elongation ...of individual protofilaments can potentially lead to an altered microtubule-end structure that promotes sudden depolymerization, termed catastrophe 1–4. However, how the dynamics of individual protofilaments relates to overall growth persistence has remained unclear. Here, we used the microtubule targeting anti-cancer drug Eribulin 5–7 to explore the consequences of stalled protofilament elongation on microtubule growth. Using X-ray crystallography, we first revealed that Eribulin binds to a site on β-tubulin that is required for protofilament plus-end elongation. Based on the structural information, we engineered a fluorescent Eribulin molecule. We demonstrate that single Eribulin molecules specifically interact with microtubule plus ends and are sufficient to either trigger a catastrophe or induce slow and erratic microtubule growth in the presence of EB3. Interestingly, we found that Eribulin increases the frequency of EB3 comet “splitting,” transient events where a slow and erratically progressing comet is followed by a faster comet. This observation possibly reflects the “healing” of a microtubule lattice. Because EB3 comet splitting was also observed in control microtubules in the absence of any drugs, we propose that Eribulin amplifies a natural pathway toward catastrophe by promoting the arrest of protofilament elongation.
•Eribulin binds to a site on β-tubulin, which is exposed at microtubule plus ends•Single Eribulin molecules induce erratic microtubule plus-end growth and catastrophes•Eribulin induces EB3 comet splitting•Eribulin amplifies a natural pathway of catastrophe induction
Doodhi et al. show that Eribulin binds to a site on β-tubulin, which is exposed at the plus ends of microtubules. Binding of single Eribulin molecules induces erratic microtubule growth, catastrophes, and splitting of EB3 comets. The authors propose that Eribulin amplifies a natural catastrophe pathway by inhibiting protofilament elongation.
•A new concept of a cogeneration system is proposed and investigated.•The system comprises solar collector, PV, SOFC and heat exchanger.•83.6% Power and heat generation efficiency has been found at ...fuel cell mode.•85.1% Efficiency of SOSE has been found at H2 production mode.•The heat to power ratio of SOFC mode has been found about 0.917.
Due to the increasing future energy demands and global warming, the renewable alternative energy sources and the efficient power systems have been getting importance over the last few decades. Among the renewable energy technologies, the solar energy coupling with fuel cell technology will be the promising possibilities for the future green energy solutions. Fuel cell cogeneration is an auspicious technology that can potentially reduce the energy consumption and environmental impact associated with serving building electrical and thermal demands. In this study, performance assessment of a co-generation system is presented to deliver electrical and thermal energy using the solar energy and the reversible solid oxide fuel cell. A mathematical model of the co-generation system is developed. To illustrate the performance, the system is considered in three operation modes: a solar-solid oxide fuel cell (SOFC) mode, which is low solar radiation time when the solar photovoltaic (PV) and SOFC are used for electric and heat load supply; a solar-solid oxide steam electrolyzer (SOSE) mode, which is high solar radiation time when PV is used for power supply to the electrical load and to the steam electrolyzer to generate hydrogen (H2); and a SOFC mode, which is the power and heat generation mode of reversible SOFC using the storage H2 at night time. Also the effects of solar radiation on the system performances and the effects of temperature on RSOFC are analyzed. In this study, 100kW electric loads are considered and analyzed for the power and heat generation in those three modes to evaluate the performances of the system. This study is also revealed the combined heat and power (CHP) efficiency of the system. The overall system efficiency achieved for the solar-SOFC mode is 23%, for the solar-SOSE mode is 20% and for the SOFC mode is 83.6%. Besides, the only electricity generation efficiency for the solar-SOFC mode is 15%, for the solar-SOSE mode is 14% and for the SOFC mode is 44.28%. An economic analysis is presented based on the annual electricity generation from the system and the system has shown the good economic viability in this study with a unit cost of energy (COE) about 0.068$/kWh.
Members of the perilipin family of lipid droplet scaffold proteins are thought to play important roles in tissue-specific regulation of triglyceride metabolism, but the mechanisms involved are not ...fully understood. Present results indicate that adipose triglyceride lipase (Atgl) interacts with perilipin-5 (Plin5) but not perilipin-1 (Plin1). Protein interaction assays in live cells and in situ binding experiments showed that Atgl and its protein activator, α-β-hydrolase domain-containing 5 (Abhd5), each bind Plin5. Surprisingly, competition experiments indicated that individual Plin5 molecules bind Atgl or Abhd5 but not both simultaneously. Thus, the ability of Plin5 to concentrate these proteins at droplet surfaces involves binding to different Plin5 molecules, possibly in an oligomeric complex. The association of Plin5-Abhd5 complexes on lipid droplet surfaces was more stable than Plin5-Atgl complexes, and oleic acid treatment selectively promoted the interaction of Plin5 and Abhd5. Analysis of chimeric and mutant perilipin proteins demonstrated that amino acids 200–463 are necessary and sufficient to bind both Atgl and Abhd5 and that the C-terminal 64 amino acids of Plin5 are critical for the differential binding of Atgl to Plin5 and Plin1. Mutant Plin5 that binds Abhd5 but not Atgl was defective in preventing neutral lipid accumulation compared with wild type Plin5, indicating that the ability of Plin5 to concentrate these proteins on lipid droplets is critical to functional Atgl activity in cells.
The enantioselective total syntheses of (+)-peniciketals A and B, two members of a family of architecturally complex spiroketals, have been achieved. Key synthetic transformations comprise Type I ...Anion Relay Chemistry (ARC) to construct the benzannulated 6,6-spiroketal skeleton, a Negishi cross-coupling/olefin cross-metathesis reaction sequence to generate the trans-enone structure, and a late-stage large fragment union exploiting our recently developed photoisomerization/cyclization tactic.
The building industry is blamed for consuming enormous natural resources and creating massive solid waste worldwide. In response to this, the concept of circular economy (CE) has gained much ...attention in the sector in recent years. Many pilot building projects that implemented CE concepts started to appear around the world, including Taiwan. However, compared with the pilot projects in the Netherlands, which are regarded as the pioneer ones by international society, many CE-related practices are not implemented in pilot cases in Taiwan. To assist future project stakeholders to recognize what the key CE-related practices are and how they could be implemented in their building projects in Taiwan, this study has conducted a series of case studies of Dutch and Taiwanese pilot projects and semi-structured interviews with key project stakeholders of Taiwanese pilot projects. Thirty key CE-related practices are identified via case studies, along with their related 5R principles (Rethink, Reduce, Reuse, Repair, Recycle) and project phases. Suggestion on CE-related practices, their 5R principles, project items, and phases to implement in building projects in Taiwan is also proposed while discussion on differences between two countries’ pilot projects is presented.
Martensite has a body-centered tetragonal (bct) structure in high carbon steels. However, body-centered cubic (bcc) {112} 〈111〉-type twins instead of bct twins always be observed as the substructure ...of martensite in high carbon steels. In this paper, martensitic substructure in a quenched high carbon Fe-1.4C (wt%) alloy has been investigated in detail using selected area electron diffraction (SAED) technique in a conventional transmission electron microscopy. The reciprocal lattice of martensite has been built based on the experimental SAED patterns. Two sets of diffraction spots (one face-centered cubic lattice and one hexagonal lattice) in the built reciprocal lattice suggest that two crystalline phases with bcc (or α-Fe) and hexagonal (ω-Fe) structure actually coexist in the twinned martensite. The two-phase diffraction spot patterns from the reciprocal lattice can match perfectly with the experimental results. The fact that the {0001}
ω
diffraction spot at the 1/3{222}
α
position and the {0002}
ω
at 2/3{222}
α
can support the ω-Fe existence in the twinned martensite.
Microtubule-stabilizing agents (MSAs) are widely used in chemotherapy. Using X-ray crystallography we elucidated the detailed binding modes of two potent MSAs, (+)-discodermolide (DDM) and the ...DDM-paclitaxel hybrid KS-1-199-32, in the taxane pocket of β-tubulin. The two compounds bind in a very similar hairpin conformation, as previously observed in solution. However, they stabilize the M-loop of β-tubulin differently: KS-1-199-32 induces an M-loop helical conformation that is not observed for DDM. In the context of the microtubule structure, both MSAs connect the β-tubulin helices H6 and H7 and loop S9-S10 with the M-loop. This is similar to the structural effects elicited by epothilone A, but distinct from paclitaxel. Together, our data reveal differential binding mechanisms of DDM and KS-1-199-32 on tubulin.
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