bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel soft members in double-layer space trusses
Authors: Hamid Yazmin Sahol , Parke Gerry , Mohd Mahdi Nur Farzana
Published: January 2019

Progressive collapse of space structures has received much attention in recent years due to the recent failure of a double-layer space truss (DLST) stadium in Terengganu, Malaysia which collapse twice in Year 2009 and 2013. There is a considerable interest in understanding the collapse behaviour of space structures and possibility of improving its collapse behaviour. This phenomenon was demonstrated by earlier researchers, such as Collins (1981) and Parke (1988) which investigated the collapse behaviour both theoretically and experimentally. In their study a carefully designed DLST structure may possess reserve of strength in excess of their elastic capacity. Although DLST have a high degree of statically degree of statically indeterminacy, not all of them are robust, as it has been found a loss of one critical member could trigger the collapse of the entire structure. Usually the collapse of the DLST is influenced by the ductility behaviour of the compression members. The aim of this study was to investigate the use of novel soft member to reduce the catastrophic progressive collapse behaviour of DLSTs. A novel soft member was constructed to measure its behaviour under tensile and compressive loads. The term novel soft member used in this study is referred to a combination of three circular tubes which is made into one component and is used to support compressive load. It was found that using a blend of three circular tubes significantly increase the ductility behaviour of the member. These test illustrates that while the inner and outer tube experience compressive forces, the middle tube will continue to increase linearly. This indicates that there is a possibility of improving the collapse behaviour of DLST by incorporating the novel soft member.
The effect of coarse aggregate hardness on the fracture toughness and compressive strength of concrete
Authors: Siregar Atur P. N. , Pasaribu Emma L. , Suarnita I Wayan
Published: January 2019

Coarse aggregate is the dominant constituent in concrete. Aggregate hardness is a variable needed to investigate in determining its effect on the critical stress intensity factors (KIC), dissipated fracture energy (Gf) and compressive strength (fc’) of the concrete. The hardness of coarse aggregate based on Los Angeles abrasion values of 16.7%., 22.6%, and 23.1% was used incorporated with Portland Composite Cement (PCC), and superplasticizer to create specimens. Cubes of 150x150x150 mm were employed to determine the fc’, and four beam sizes: 50x100x350 mm, 50x150x500 mm, 50x300x950 mm and 50x450x1250 mm were engaged to determine KIC and Gf. The fc’ and Gf of specimens manufactured by three different hardness of coarse aggregates were 45, 43, 40 MPa and 89.4, 54.0, 56.3 N/m respectively. KIC of specimens was 138.9, 119.4 and 114.1 MPa.mm1/2 for beam size of 50x100x350 mm; 148.2, 115.8 and 108.8 MPa.mm1/2 for beam size of 50x150x500 mm; 230.9, 183.1 and 157.9 MPa.mm1/2 for beam size of 50x300x950 mm; and 293.2, 248.1 and 244.3 MPa.mm1/2 for beam size of 50x450x1250 mm. Experimental results showed that decreasing hardness of coarse aggregate was found to have significant effect on the fracture toughness rather than on the compressive strength of concrete.
Behavior of wood beam connection using staples subjected to in-plane moment
Authors: Lenggani Farida , Suryoatmono Bambang
Published: January 2019

It is very frequent that solid wood beams need to be connected one to another to obtain a longer beam. In this study, the behavior of solid wood beams connections using plywood sheets as connecting elements and staples as mechanical fasteners were studied experimentally. The experimental results were compared with elastic analyses. Both beam and plywood were made of meranti (shorea). The staple type was MAX 1022J. This study was conducted on two specimens. The first specimen had two rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 40 staples. The second one had three rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 60 staples. From the tests, it can be concluded that each material in the connection, namely wood beam, plywood, and staples, failed. Failure mode of the wood beam was in the form of crack and tear. Failure mode of the plywood was the damage of the plywood directly contacted with the crown of the staples. Failure modes of the staples were flexural yielding. The differences between connection strength obtained from tests and elastic analyses were 8.18% for the first specimen and 0.65% for the second specimen, with the test results were higher than the elastic analyses results. It can be concluded that elastic analysis is quite accurate and conservative to estimate the strength of this type of connection, provided that the lateral resistance of connection with a staple is known.
Behaviour of Reinforced Concrete Frames with Central Opening Masonry Infill under Lateral Reversed Cyclic Loading.
Authors: Maidiawati  , Tanjung Jafril , Hayatfi Yulia , Medriosa Hamdeni
Published: January 2019

This paper will describe the seismic behaviour of masonry infilled RC frame with a central opening structure under reversed cyclic lateral loading. To achieve the purpose of this study, four 1/4-scale single story and single bay RC frame specimens were tested, i.e. one bare frame, one clay brick masonry infilled RC frame without opening and two clay brick masonry infills with a central opening in infills. The ratios of opening size to panel area were 25% and 40%. Through reversed cyclic lateral loading tests, the seismic performance of RC frames with a central opening brick masonry infills was investigated. As the results, significant distinctions of failure mechanism, lateral strength, stiffness, and ductility were observed between these specimens. In the case of infills with a central opening, the cracks sprouted and developed at the corners of the opening. Although the presence of the opening in infill reduces the lateral strength and stiffness overall structure, the brick infilled frames with a central opening of 25% and 40% of panel area show better seismic performance as compared to the bare frame.
Dynamic response of long-span bridges subjected to nonuniform excitation: a state-of-the-art review
Authors: Yadi Seplika , Suhendro Bambang , Priyosulistyo Henricus , Aminullah Akhmad
Published: January 2019

In recent years, considerable attention has been paid to the research of dynamic response of long-span bridges with particular emphasis on seismic behavior. Cable-stayed and suspension bridges are the most popular types. Since long-span bridges have multi-supports and extreme lengths, due to the spatial variation effects, the ground motions at different supports might be non-uniform. A state-of-the-art update review of the response of long-span bridges subjected to non-uniform excitation is presented. The review mainly focuses on the theoretical aspects of non-uniform excitation, numerical studies, and experimental studies to verify some of the theoretical findings. In this paper, a review of the use of shake-table in experimental studies of long-span bridges is also presented. The non-uniform cases considered include a time delay with the same support excitations, multiple support excitations, and the combination of the first and the later. The results are discussed and summarized in comparison to the cases of uniform support excitation.
Measurement of RC slab surface shape and investigation of local water stagnation
Authors: Yasuda Yuko , Kakuma Ko , Shiroto Yoshitaka , Matsumoto Takashi
Published: January 2019

In a road bridge, drainage facilities are installed to discharge the water on the bridge surface. For each drainage facility, installation spacings are exemplified by waterproof manuals and others, but the quantitative sharing and drainage capacity of each facility and bridge surface have not been clarified. Also, it is thought that water will be stagnant due to bridge surface irregularities generated during construction or during service. However, no regulations on the concavities and convexities about the slab surface are clearly shown in construction standards. Therefore, in this study, surface shape measurement and water sprinkling test on unpaved actual bridge slab were carried out. From the results, we confirmed the possibility that irregularities on the slab surface affect the tendency of local water stagnation. Since only one bridge was studied in the current study, we have not confirmed the influence of gradient magnitude on the drainage capacity of uneven slab surface. It is a future task to clarify the relation between surface gradient and allowable irregularity size and to develop a standard for controlling irregularities on slab and pavement surface.
On the capacity of high, moderate and low earthquake frequency content to cause global drift ratio at level-2 of structural performance
Authors: Pawirodikromo Widodo
Published: January 2019

The earthquake (EQ) frequency content can be high, moderate or low frequency, mainly depends on epicenter’s distance and local soil conditions. The EQ frequency content will affect on the inelastic response of building structures. According to Vision 2000 and FEMA 356 under particular hazard level, the building is expected to perform structural response either fully operational, immediate occupancy, life safety or near collapse. Numerical investigation of 10-stories mid-rise reinforced concrete frame structure subjected to variations of the earthquake frequency contents has been conducted. The building model is assumed to be located at Yogyakarta on the soft soil condition. The building model it was shaken by various EQ frequency contents and maximum ground accelerations (PGA) until approaching the global drift ratio (GDR) of 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 %. Result of investigation show that the EQ high frequency is almost impossible to cause GDR ± 2.0% since it needs PGA as high as 4.01g. Under the possible maximum recorded PGA in the field, the only EQ with low frequency content which has capacity to cause maximum GDR reaches ± 2.0%. or at maximum of structural performance level. Between GDR and overall damage index (ODI) is linearly correlated, however boundaries of the performance levels according to GDR and ODI does not meet at the same point.
Structural analysis using three-component acceleration time histories caused by shallow crustal fault earthquakes with a maximum magnitude of 7 Mw
Authors: Partono Windu , Ami Priastiwi Yulita , Nuroji  , Dwi Atmanto Indrastono , Pardoyo Bambang , Octaviani Gultom Trinita , Tampubolon Yanuar
Published: January 2019

Research on the improvement of Indonesian seismic hazard maps has already been carried out by the National Center for Earthquake Studies in 2017. One important global data obtained from this research related with all earthquake sources mechanism which might be used for building design and evaluation. Based on this research there are two important and closest earthquake sources to Semarang, Lasem fault (strike slip mechanism) and Semarang fault (reverse mechanism). This paper presents the dynamic structural evaluations of the hospital building (approximately 49 meters height) located in Semarang, Indonesia, by conducting two seismic load functions, two-component surface spectral acceleration (X and Y directions) developed from Indonesian Seismic Code SNI:1726-2012 and three-component (North-South, East-West and Vertical) of surface acceleration time histories. All acceleration time histories were modified from three earthquake events which represents Semarang fault earthquake scenarios and developed from earthquake events with magnitude from 6.3 to 6.9 Mw and the maximum distance of building to earthquake epicentre 15 Km. Based on the floor deformation and the drift ratio results calculated using dynamic analysis, the building is predicted has the capability on resisting earthquake scenarios up to a maximum magnitude 7 Mw with minimum epicentre distance 10 Km.
The effect of water binder ratio on strength development of class C fly ash geopolymer mortar prepared by dry geopolymer powder
Authors: Wardhono Arie
Published: January 2019

The use of geopolymer binder as cement replacement material can reduce the amount of carbon dioxide gas produced during the Portland Cement manufacturing process. However, the main issue of geopolymer binder is in the mixing process of sodium silicate and NaOH which requires specialized knowledge and strict supervision. This paper reports the effect of water binder ratio on strength development of fly ash geopolymer mortar using dry geopolymer powder. Fly ash with high calcium content was used as primary material. The dry geopolymer powder was prepared by wet mixing method which was made by drying a mixture of NaOH solution and limestone for 24 hours. The variations of water to binder ratio were 0.30, 0.35, 0.40, 0.45, and 0.50. Strength properties were measured by compressive strength at the age of 7, 14 and 28 days. The results showed that the water binder ratio significantly affect the strength development of geopolymer mortar prepared by dry geopolymer powder. The water binder ratio of 0.40 gives the highest compressive strength of 10.3 MPa at 28 days. This suggests that the use of dry geopolymer powder on geopolymer mortar production can overcome the difficulties of geopolymer mortar mixing on site.
Risk evaluation for the navigation environment of the LNG ship based on the cloud model
Authors: Zhang Shiyuan , Li Lianbo , Li Xinze
Published: January 2019

In order to enhance water transport safety of the LNG ship and improve the objectivity of risk assessment of LNG ships navigation environment, the cloud model which can realize the conversion between qualitative and quantitative evaluation indexes is used to evaluate the LNG ships navigation environment. Combined with the Delphi method, cloud weight and cloud model of indexes at all levels in the evaluation system are determined. At the same time, simulation is carried out by MATLAB software and cloud chart is obtained. And then we analyze the risk level of different factors in LNG ships navigation environment to get the evaluation results, which provides decision-making basis for navigation safety management. Overall, it is testified that the cloud model can reduce the randomness and fuzziness in the process of evaluating and the irrationality caused by the subjective assumption of weight distribution, which makes the results more reasonable and credible.
Research on Anomie Behavior of Drivers on Non-physical Isolated Urban Road Based on Game Theory
Authors: Li Meiye , Li Meiying , Hu Xiaoxia , Li Ge
Published: January 2019

In order to overtake motor vehicles ahead, some motor vehicles tend to enter non-motorized lane illegally on non-physical isolated urban road, which cause a negative influence on non-motor vehicles. In this paper, this anomie behavior is studied by headway distribution function, fluid dynamics model and game theory. Utilize headway distribution function to calculate the probability of critical gap required for motor vehicles entering non- motorized lanes, and fluid mechanics model to analysis delay. After that, considering critical gap, delay, management expense and fine for anomie behavior, the time value functions of drivers and cyclists are established and regarded as the payment functions in mixed strategy Nash equilibrium. Finally, according to the result of Nash equilibrium, two optimal probability models are put forward. Under different circumstances of non-motor vehicle flow, motor vehicle speed, management expense and fine for anomie behavior, the first model quantified the optimal probability that drivers commit anomie behavior and the second model quantified the optimal probability that traffic department implements management. Furthermore, models can provide references for the management of anomie behavior on non-physical isolated urban road.
Minimizing Energy Loss over Distance and Activating the Energy Trading System in Microgrid
Authors: Lee Sang Hyeon , Choi Myeong-in , Lee SangHoon , Park SoungHoan , Park Sehyun
Published: January 2019

As small-scale distributed energy is gradually expanding, commercialization of peer to peer(P2P) energy trading that freely exchanges energy among individuals in various countries is being commercialized, and the Microgrids (MGs) are considered to be an optimal platform for P2P energy trading. Although conducting electricity trade among individuals without going through power companies is still in its infancy, it is expected to expand gradually as the awareness of the shared economy grows and the MG spreads. Research on more efficient trading systems is needed while trading energy in MG. Therefore we propose a more efficient energy trading system that minimizes the loss in proportion to the distance of the power line when energy trading is performed in the MG. We have constructed a virtual MG environment and experimented with energy trading scenarios. As a result, when the algorithm is applied, loss in proportion to the distance is reduced by 2.495% and energy trading becomes more active. The amount of energy and the number of trades increased by 1.5 times during the energy trading process.
The Research of Short-circuit Calculation and Optimization of Contain Distributed Power Distribution Network
Authors: Yu Haiyang , Zu Guangxin , Zhang Meilun , Liu Zhipeng , Wu Guoliang , Zheng Jun , Guan Wanlin
Published: January 2019

Electric power industry as an indispensable energy supply in daily life and production, which is the main motive force of equipment operation in the industrial times. Therefore, in order to meet the development needs and ensure the safety of power supply, it is necessary to optimize and transform the power grid. So that energy conservation and security of supply and demand can be ensured. In this paper, the short-circuit calculation and optimization design of distributed power distribution network are studied deeply, aiming at improving the performance of power grid and promoting the rapid development and transformation of power industry.
Development of an Optimization Model to Manage Imbalances in Power Systems by Local Power Retail Companies
Authors: Matsuhashi Ryuji
Published: January 2019

The feed-in tariff (FIT) programs resulted in rapid growth of renewable power sources in various countries. In Japan, the program particularly triggered explosive growth of solar power generations because of its short lead-time and high tariff level. Although mass introduction of renewable power sources certainly contributes to reduce CO2 emissions, it causes serious instability issues in power systems. One of the most serious issues is management of imbalances resulting from forecast errors in solar power generations. These imbalances must be compensated so as to keep stable operation in power systems. On the other hand, local power retail companies are increasing nowadays in various countries including Japan. These companies are mainly procuring renewable power sources such as solar power systems.Taking these circumstances into consideration, this article aims at exploring measures to manage the imbalances of power systems by local power retail companies. For this purpose, we developed a model in mixed integer linear programming to operate power systems dealing with the imbalances. Evaluated results using the model indicated the followings; appropriate adoption of stationary or home batteries is shown to economically compensate the imbalances by local power retail companies.
Study on AC Resistance of Layering Enamelled Stranded Conductor
Authors: Jiang Zhenxing , Yang Liming , Zhu Zhien
Published: January 2019

In recent years, with the rapid development of large-length ultra-high-pressure voltage extrusion insulated submarine cable technology, the cable system in the medium-length offshore power grid interconnection project has been gradually replaced by XLPE insulation by traditional oil-paper insulation. There are many large cross-section conductors used in long-distance power transmission cables, and according to the IEC 60287-1-1, it is recommended to use Milliken conductors to reduce the AC resistance of conductors, at the same time, in submarine cables, there is a high requirement on the water-blocking performance of conductors and the water resistance of Milliken conductors is poor, so it is not used in submarine cable conductors. This paper puts forward a layering enamelled stranded conductor and a calculation method of AC / DC resistance ratio for it. The validity of the calculation method is verified by experimental tests. At the same time, the calculation shows that the AC / DC resistance of the conductor at 1800 mm2 nominal cross section can be reduced by 16% compared with the conventional round compacted conductor in the prior art. The effectiveness of this conductor in reducing AC resistance is verified by finite element simulation.
Analysis on the feasibility of small-scale biogas from palm oil mill effluent (POME) – Study case: Palm oil mill in Riau-Indonesia
Authors: Nuryadi A P , Raksodewanto A A , Susanto H , Peryoga Y
Published: January 2019

The province of Riau has the most significant palm oil plantation in Indonesia which has the potential of the palm oil mill effluent (POME). One way to use this liquid waste is by the anaerobic process into biogas to generate electricity. Based on the assumption of calculated liquid waste can produce biogas about 538 m3 / hour or equal to 4,600 MJ / hour potentially generate electricity about 1 MW. This paper discusses the scheme of the POME Biogas Power Plant project which benefits the palm oil mill which is Built-operate-transfer (BOT) with a duration of 15 years selected as a reference. With this duration obtained IRR of 17.47% higher than at WACC of 15.61% and a payback period of 5.63 years. The 15-year duration gives Investor resilience in case of an increase of loan interest rate to 13% during the repayment period. Also, the use of alternative schemes that may be pursued by biogas products from cleaned digesters is then used as gas fuel to operate diesel generators. Plant Alternative for BOT duration for five years. The project is very feasible to be implemented with a very high IRR (37.56%) score when compared to WACC (15.61%).
Investigation of water distribution features among pipes in BF hearth
Authors: Jiao Ke-xin , Zhang Jian-liang , Wang Guangwei , Chen Chunlin
Published: January 2019

The cooling system is important for the safety of blast furnace production. Measurements for over six months on a 1350 m3 blast furnace have shown that water volume distribution among the pipes in hearth is not uniform. The nature of the water volume distribution curve remains constant while furnace operation is normal, but is influenced by features of heat flux and hydrodynamic to the bustle pipe, which result in a 40–60% difference between maximum and minimum flow rates through individual pipe assemblies. A change in water volume is generally taken up by pipes that are working well. The water volume varies by 20–40% between pipes. That the problem about water non-uniform distribution of water-supplying system in cooling system is caused by the hydrodynamic pulsations existed between the parallel pipes and individual pipe. The cooling water temperature difference and water volume shows negative relationship. There may be some false positives of hearth erosion trends when the state of erosion is determined by water temperature difference for the non-uniform distribution of water volume. The inhomogeneity of the cooling intensity among the pipes merits attention.
Palliative Care for Neurologically Injured Patients: Why and How?
Authors: Bindu Barkha , Rath Girija P.
Published: January 2019

The role of palliative care in patients with cancer is widely acknowledged and practiced. Though its role in chronic, progressive, and incurable neurological conditions is being recognized now, it is not widely practiced. Lack of awareness and training are important factors contributing to this. Neurological patients differ from oncological patients with respect to their symptoms, fluctuating disease course, varied prognoses, and difficulty in identifying end-of-life stage. Knowledge of different neurological conditions is important to practice neuropalliative care appropriately. Growth of neuropalliative care services must begin with the neurologist at the center of the multidisciplinary team. Neurologists need to be trained in communication skills and advance care planning, and must be aware of end-of-life care, do-not-resuscitate policies, and withdrawal of life support measures. This article elaborates on these aspects of neuropalliative care and discusses its role in various neurological conditions.
Anesthetic Challenges of a Child with Sturge–Weber Syndrome for Epilepsy Surgery: A Case Report
Authors: Kurian Roshan , Lionel Karen R. , Mariappan Ramamani
Published: January 2019

Sturge–Weber syndrome is a rare congenital disease, also called encephalotrigeminal angiomatosis, caused by persistence of transitory primordial arteriovenous connections of the fetal intracranial vasculature. It is characterized by vascular malformations with capillary venous angiomas that involve the face, choroid of the eye, and leptomeninges. The main clinical features of this syndrome are port-wine stains, glaucoma, convulsions, and angiomas of the airway. Anesthesia management is directed toward anticipating a difficult airway, avoiding trauma to the hemangioma during airway manipulation, preventing the rise in the intracranial and intraocular pressures, anticipating and managing massive blood loss and the complications associated with massive blood transfusion, and avoiding factors that might trigger a seizure such as hypoxia, hypercarbia, hypotension, hypoglycemia, and hyperthermia.
Trazodone: A New Antiepileptic Drug for Dravet Syndrome?
Authors: Azevedo Kauppila Linda , Amorim Isabel , Bentes Carla , Peralta Ana Rita
Published: January 2019

Dravet syndrome (DS) is associated with severely refractory seizures. Recent studies suggest possible antiepileptic effects of serotonergic drugs. We report the case of a 25-year-old woman with DS-related epilepsy (SCN1A mutation), with daily seizures since childhood, associated with developmental delay. Several antiepileptic drug regimens were tested, without clear benefit. Over the years, she maintained a pattern of diurnal and nocturnal seizures, with a nocturnal predominance averaging two tonic–clonic seizures per night, with periods of seizure clusters. On routine electroencephalography (EEG), frequent, subtle myoclonic seizures during sleep were detected. A seizure-free period or significant reduction in seizure frequency was never attained. Trazodone was started due to insomnia. This led to a remarkable as well as long-standing clinical and neurophysiological improvement: less than one reported tonic–clonic seizure per month during the next 18 months, reduction in interictal epileptiform activity (170/h vs. 30/h of sleep), myoclonic seizures (90/h vs. 0.7/h of sleep), and tonic–clonic seizures (2/night to 0) on video-EEG. Serotonergic pathway modulation effects on DS-related epilepsy were observed in animal studies, in addition to small case series using lorcaserin and fenfluramine. To the best of our knowledge, no clinical data exist showing that trazodone may be an efficacious agent in patients with DS. Despite limitation of an isolated case with possible chance factors, our data, given the striking effect, provide this clinical evidence for the first time, and may have important clinical implications in patients with DS, reinforcing the need for further research on this subject.
Modified Kunlin's Technique for Microsurgical End-to-End Anastomoses: A Series of 100 Flaps
Authors: Inbal Amir , Collier Zachary Jonathan , Ho Chien-Liang , Gottlieb Lawrence Jay
Published: January 2019

Background In 1949, a French vascular surgeon, Jean Kunlin, first described a venous end-to-side anastomotic technique to address large vessel size mismatches. It was later modified by Dr. Robert Linton for end-to-end (ETE) anastomoses on the “macrovascular” scale. While multiple procedures exist for addressing moderate caliber discrepancies, few safely and reliably compensate for marked diameter differences at the microvascular level. In this study, we present the first large series adapting a modified geometric Kunlin's technique for arterial and venous ETE anastomoses in reconstructive microsurgery.

Methods We reviewed 100 consecutive cases of free flap reconstructions from 2006 to 2015 utilizing a modified geometric Kunlin's technique for arterial and venous ETE anastomoses. Patient demographics and flap outcomes were analyzed. Overall flap survival rates and postoperative complications were analyzed and compared with standard values in the microsurgical literature.

Results A total of 146 ETE anastomoses from 100 free flaps were analyzed. The average patient age was 51 ± 3.1 years (range: 10–84 years). Free flaps in this study were used for gender confirmation phalloplasties (20%) and reconstructing defects of the head and neck (63%), extremities (16%), and trunk (1%). There was a total of 17 takebacks including 5 for hematoma, 8 for anastomotic thromboses (6 venous), and 4 without any identifiable complication. Of these takebacks, two partial and two complete flap losses occurred. There was an 88% salvage rate for flaps requiring takebacks during the postoperative period. Overall, flap survival rate was 98% including those with complications or takebacks.

Conclusion The modified Kunlin's technique is a reliable, facile, and versatile method of performing ETE anastomoses for arterial and venous vessels, especially with vessel diameter mismatches of 3:1 or greater, as well as for challenging orientations. Notably, it provides equivalent flap survival and complication rates as compared with other techniques in the microsurgical literature.
15.6.3 Isoquinolinones (Update 2018)
Authors: Glushkov V. A. , Shklyaev Yu. V.
Published: January 2019

This chapter is an update to the earlier Science of Synthesis contribution describing methods for the synthesis of isoquinolin-1(2H)-ones and isoquinolin-3(2H)-ones. The focus is on the literature published in the period 2005-2015, and includes new cyclization reactions, C-H activation methods, and catalysis by metal complexes of nickel, ruthenium, rhodium, and palladium.
31.5.1.5.12 Synthesis of Phenols from Nonaromatic Precursors (Update 2018)
Authors: González-Bello C.
Published: January 2019

The introduction, or chemical modification, of substituents on an existing aromatic ring is probably the most widely employed strategy for the synthesis of phenols, and these methods are summarized in Sections 31.5.1.1 to 31.5.1.4. However, with such transformations, it is sometimes difficult to achieve satisfactory regiocontrol. Furthermore, the required precursors may be expensive, difficult to synthesize, or simply unavailable. The direct construction of a phenol ring from acyclic precursors that already bear the required substituents at the appropriate positions represents a good alternative. This strategy is particularly useful for the synthesis of highly substituted phenols. In this chapter, an update of the reported methods for this approach, which were originally described in Section 31.5.1.5 of Science of Synthesis in 2007, is provided, and includes methods for benzannulation, cycloaromatization, cyclocondensation, and ring-closing metathesis.
Kinetic effects on neutron generation in moderately collisional interpenetrating plasma flows
Authors: Higginson D. P. , Ross J. S. , Ryutov D. D. , Fiuza F. , Wilks S. C. , Hartouni E. P. , Hatarik R. , Huntington C. M. , Kilkenny J. , Lahmann B. , Li C. K. , Link A. , Petrasso R. D. , Pollock B. B. , Remington B. A. , Rinderknecht H. G. , Sakawa Y. , Sio H. , Swadling G. F. , Weber S. , Zylstra A. B. , Park H.-S.
Published: January 2019

Collisional kinetic modifications of ion distributions in interpenetrating flows are investigated by irradiating two opposing targets, either CD/CD or CD/CH, on the National Ignition Facility. In the CD/CD case, neutron time-of-flight diagnostics are successfully used to infer the ion temperature, 5–6 keV, and velocity, 500 km/s per flow, of the flows using a multi-fluid approximation of beam-beam nuclear fusion. These values are found to be in agreement with simulations and other diagnostics. However, for CD/CH, the multi-fluid assumption breaks down, as fusion is quasi-thermonuclear in this case and thus more dependent on the details of the ion velocity distribution. Using kinetic-ion, hydrodynamic-electron, and hybrid particle-in-cell modeling, this is found to be partially due to a skewed deviation from a Maxwellian in the ion velocity distribution function resulting from ion-ion collisions. This skew causes a downshift in the mean neutron velocity that partially resolves the observation in the CD/CH case. We note that the discrepancy is not completely resolved via collisional effects alone and may be a signature of collisionless electromagnetic interactions such as the Weibel-filamentation instability.
Spatial imaging of charge transport in silicon at low temperature
Authors: Moffatt R. A. , Kurinsky N. A. , Stanford C. , Allen J. , Brink P. L. , Cabrera B. , Cherry M. , Insulla F. , Ponce F. , Sundqvist K. , Yellin S. , Yen J. J. , Young B. A.
Published: January 2019

We present direct imaging measurements of charge transport across a 1 cm × 1 cm × 4 mm crystal of high purity silicon (∼20 kΩ cm) at temperatures between 500 mK and 5 K. We use these data to determine the intervalley scattering rate of electrons as a function of the electric field applied along the ⟨111⟩ crystal axis, and we present a phenomenological model of intervalley scattering which explains the constant scattering rate seen at low-voltage for cryogenic temperatures. We also demonstrate direct imaging measurements of effective hole mass anisotropy, which is strongly dependent on both temperature and electric field strength. The observed effects can be explained by a warping of the valence bands for carrier energies near the spin-orbit splitting energy in silicon.
Mitigation of cosmic ray effect on microwave kinetic inductance detector arrays
Authors: Karatsu K. , Endo A. , Bueno J. , de Visser P. J. , Barends R. , Thoen D. J. , Murugesan V. , Tomita N. , Baselmans J. J. A.
Published: January 2019

For space observatories, the glitches caused by high energy phonons created by the interaction of cosmic ray particles with a detector substrate lead to dead time during observation. Mitigating the impact of cosmic rays is therefore an important requirement for detectors to be used in future space missions. In order to investigate possible solutions, we carry out a systematic study by testing four large arrays of Microwave Kinetic Inductance Detectors (MKIDs), each consisting of ∼960 pixels and fabricated on monolithic 55 mm × 55 mm × 0.35 mm Si substrates. We compare the response to cosmic ray interactions in our laboratory for different detector arrays: A standard array with only the MKID array as reference, an array with a low Tc superconducting film as a phonon absorber on the opposite side of the substrate, and arrays with MKIDs on membranes. The idea is that the low Tc layer down converts the phonon energy to values below the pair breaking threshold of the MKIDs, and the membranes isolate the sensitive part of the MKIDs from phonons created in the substrate. We find that the dead time can be reduced up to a factor of 40 when compared to the reference array. Simulations show that the dead time can be reduced to below 1% for the tested detector arrays when operated in a spacecraft in an L2 or a similar far-Earth orbit. The technique described here is also applicable and important for large superconducting qubit arrays for future quantum computers.
Solving the Schrödinger equation with the free-complement chemical-formula theory: Variational study of the ground and excited states of Be and Li atoms
Authors: Nakatsuji Hiroshi , Nakashima Hiroyuki
Published: January 2019

The chemical formula theory (CFT) proposed in Paper I of this series [H. Nakatsuji et al., J. Chem. Phys. 149, 114105 (2018)] is a simple variational electronic structure theory for atoms and molecules. The CFT constructs simple, conceptually useful wave functions for the ground and excited states, simultaneously, from the ground and excited states of the constituent atoms, reflecting the spirits of the chemical formulas. The CFT wave functions are also designed to be used as the initial wave functions of the free complement (FC) theory, that is, the exact theory producing the exact wave functions of the Schrödinger accuracy. This combined theory is referred to as the FC-CFT. We aim to construct an exact wave function theory that is useful not only quantitatively but also conceptually. This paper shows the atomic applications of the CFT and the FC-CFT. For simplicity, we choose the small atoms, Be and Li, and perform variational calculations to essentially exact levels. For these elements, a simple Hylleraas CI type formulation is known to be potentially highly accurate: we realize it with the CFT and the FC-CFT. Even from the CFT levels, the excitation energies to the Rydberg excited states were calculated satisfactorily. Then, with increasing the order of the FC theory in the FC-CFT, all the absolute energies and the excitation energies of the Be and Li atoms were improved uniformly and reached rapidly to the essentially exact levels in order 3 or 4 with moderately small calculational labors.
Dynamics of finite dimensional non-hermitian systems with indefinite metric
Authors: Ramírez Romina , Reboiro Marta
Published: January 2019

We discuss the time evolution of physical finite dimensional systems which are modelled by non-hermitian Hamiltonians. We address both general non-hermitian Hamiltonians and pseudo-hermitian ones. We apply the theory of Krein Spaces to construct metric operators and well-defined inner products. As an application, we study the stationary behavior of dissipative one axis twisting Hamiltonians. We discuss the effect of decoherence under different coupling schemes.
Prediction of atomization energy using graph kernel and active learning
Authors: Tang Yu-Hang , de Jong Wibe A.
Published: January 2019

Data-driven prediction of molecular properties presents unique challenges to the design of machine learning methods concerning data structure/dimensionality, symmetry adaption, and confidence management. In this paper, we present a kernel-based pipeline that can learn and predict the atomization energy of molecules with high accuracy. The framework employs Gaussian process regression to perform predictions based on the similarity between molecules, which is computed using the marginalized graph kernel. To apply the marginalized graph kernel, a spatial adjacency rule is first employed to convert molecules into graphs whose vertices and edges are labeled by elements and interatomic distances, respectively. We then derive formulas for the efficient evaluation of the kernel. Specific functional components for the marginalized graph kernel are proposed, while the effects of the associated hyperparameters on accuracy and predictive confidence are examined. We show that the graph kernel is particularly suitable for predicting extensive properties because its convolutional structure coincides with that of the covariance formula between sums of random variables. Using an active learning procedure, we demonstrate that the proposed method can achieve a mean absolute error of 0.62 ± 0.01 kcal/mol using as few as 2000 training samples on the QM7 dataset.
Overlap in fish assemblages observed using pelagic and benthic baited remote underwater video stations
Authors: Clarke Thomas M. , Whitmarsh Sasha K. , Fairweather Peter G. , Huveneers Charlie
Published: January 2019

Baited remote underwater video stations (BRUVS) are increasing in popularity as non-invasive and fishery-independent tools for assessing fish assemblages. Although most BRUVS studies have focused on benthic fish communities, recent studies also use BRUVS to examine the comparatively undersampled pelagic communities. However, the propensities of benthic BRUVS to detect pelagic fishes and, likewise, pelagic BRUVS to detect demersal fishes are unknown. This study simultaneously used benthic and pelagic BRUVS deployed either separately (single) or in combination to determine assemblages of demersal and pelagic species at three contrasting sites within temperate South Australia. Assemblages observed by benthic v. pelagic BRUVS differed significantly at all sites, including one as shallow as 7m deep, but there were no significant differences in assemblages observed between BRUVS of the same position (i.e. pelagic or benthic) when BRUVS were deployed as single units or in combination. This study reveals the limitations of using only benthic or pelagic BRUVS, and highlights the necessity for both BRUVS positions to be used together to ensure that a comprehensive representation of entire fish assemblages throughout the water column can be obtained.
Identifying coupled clusters of allostery participants through chemical shift perturbations
Authors: Xu Yunyao , Zhang Dongyu , Rogawski Rivkah , Nimigean Crina M. , McDermott Ann E.
Published: January 2019

Significance

Allostery is a common strategy used by nature to transmit information in proteins, including membrane signaling systems, wherein binding of one ligand affects avidity for binding another ligand in a distal site. Methods are needed for elucidation of functional groups that are critical for coupling between the binding sites, which we call allosteric participants. Identifying and characterizing allosteric participants is important for understanding the allosteric mechanism and crucial for developing new drugs. We develop an NMR method to detect allosteric participants that relies on their multistate nature, and we apply this method to a membrane protein, the potassium channel KcsA. We confirm the importance of specific amino acid side chains for allostery through analysis of binding affinities.
Exploring fast proton transfer events associated with lateral proton diffusion on the surface of membranes
Authors: Amdursky Nadav , Lin Yiyang , Aho Noora , Groenhof Gerrit
Published: January 2019

Significance

Proton diffusion (PD) across biological membranes is a fundamental process in many biological systems, such as in aerobic respiration or in the photosynthesis process. Even though this diffusion process has been studied for many decades, it is still highly enigmatic. Here, we suggest an experimental technique to study the very fast PD events taking place upon the photoinduced release of a proton on the surface of the membrane. We show that the diffusion, as well as the interaction between protons on the surface and protons in bulk media can be influenced by the nature of the membrane’s lipids. Our results shed some light on this unique PD process and help to overcome previous experimental contradictions in the literature.
Discovery of potent SOS1 inhibitors that block RAS activation via disruption of the RAS–SOS1 interaction
Authors: Hillig Roman C. , Sautier Brice , Schroeder Jens , Moosmayer Dieter , Hilpmann André , Stegmann Christian M. , Werbeck Nicolas D. , Briem Hans , Boemer Ulf , Weiske Joerg , Badock Volker , Mastouri Julia , Petersen Kirstin , Siemeister Gerhard , Kahmann Jan D. , Wegener Dennis , Böhnke Niels , Eis Knut , Graham Keith , Wortmann Lars , von Nussbaum Franz , Bader Benjamin
Published: January 2019

Since the late 1980s, mutations in theRASgenes have been recognized as major oncogenes with a high occurrence rate in human cancers. Such mutations reduce the ability of the small GTPase RAS to hydrolyze GTP, keeping this molecular switch in a constitutively active GTP-bound form that drives, unchecked, oncogenic downstream signaling. One strategy to reduce the levels of active RAS is to target guanine nucleotide exchange factors, which allow RAS to cycle from the inactive GDP-bound state to the active GTP-bound form. Here, we describe the identification of potent and cell-active small-molecule inhibitors which efficiently disrupt the interaction between KRAS and its exchange factor SOS1, a mode of action confirmed by a series of biophysical techniques. The binding sites, mode of action, and selectivity were elucidated using crystal structures of KRASG12C–SOS1, SOS1, and SOS2. By preventing formation of the KRAS–SOS1 complex, these inhibitors block reloading of KRAS with GTP, leading to antiproliferative activity. The final compound 23 (BAY-293) selectively inhibits the KRAS–SOS1 interaction with an IC50of 21 nM and is a valuable chemical probe for future investigations.
Zn-dependent bifunctional proteases are responsible for leader peptide processing of class III lanthipeptides
Authors: Chen Shaoming , Xu Bing , Chen Erquan , Wang Jiaqi , Lu Jingxia , Donadio Stefano , Ge Huiming , Wang Huan
Published: January 2019

Significance

Lanthipeptides represent one of the largest classes of peptide natural products with a ribosomal origin, and their maturation requires a designated protease(s) to remove the N-terminal leader peptides after core peptide modifications are properly installed. For class III lanthipeptides, the identity of the protease(s) responsible for leader processing remains unclear, posing a major obstacle to their heterologous production and bioengineering. This study reveals that an unprecedented class of bifunctional Zn-dependent proteases is universally responsible for the leader removal of class III lanthipeptides, thereby clarifying the long-standing question regarding the biosynthesis of this emerging group of natural products. Our study should facilitate the discovery and bioengineering of class III lanthipeptides in the future.
Magnetic control of graphitic microparticles in aqueous solutions
Authors: Nguyen Johnny , Conca Dario Valter , Stein Johannes , Bovo Laura , Howard Chris A. , Llorente Garcia Isabel
Published: January 2019

Significance

This paper presents the magnetic transport of diamagnetic graphite microparticles in water solutions. Given the dominance of viscous drag forces at the microscale, moving a microparticle that is submerged in liquid is comparably as hard as moving a macroparticle within dense honey. While diamagnetism is a weak magnetic property, for graphite it can be exploited to generate useful transport in liquid. The contactless magnetic control of biocompatible micrographite, together with graphite’s unique physical properties, opens up possibilities for applications in sensing, analysis, synthesis, and diagnosis in chemistry, biology, medicine, and physics.
Peptidic degron for IMiD-induced degradation of heterologous proteins
Authors: Koduri Vidyasagar , McBrayer Samuel K. , Liberzon Ella , Wang Adam C. , Briggs Kimberly J. , Cho Hyejin , Kaelin William G.
Published: January 2019

Significance

Systems for degrading proteins at will are useful for a variety of biological experiments. Although a number of such systems have been described, they vary widely in terms of complexity, ease of obtaining the necessary reagents, and costs. Moreover, no one system seems to work for all proteins, and the ideal system often must be determined empirically. Thalidomide-like drugs (IMiDs) reprogram the ubiquitiously expressed cereblon ubiquitin ligase complex to degrade the lymphocyte transcription factors IKZF1 and IKZF3. Here, we show that an IKZF3-derived 25mer constitutes a modular degron that can be used to target heterologous proteins for destruction by IMiDs, which are widely available and cross the blood–brain barrier, in cell culture and in mouse experiments.