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Insect olfactory receptors (iORs) with atypical 7-transmembrane domains, unlike Chordata olfactory receptors, are not in the GPCR protein family. iORs selectively bind to volatile ligands in the environment and affect essential insect behaviors. In this study, we constructed a new platform (iORbase, https://www.iorbase.com) for the structural and functional analysis of iORs based on a combined algorithm for gene annotation and protein structure prediction. Moreover, it provides the option to calculate the binding affinities and binding residues between iORs and pheromone molecules by virtual screening of docking. Furthermore, iORbase supports the automatic structural and functional prediction of user-submitted iORs or pheromones. iORbase contains the well-analyzed results of approximately 6 000 iORs and their 3D protein structures identified from 59 insect species and 2 077 insect pheromones from the literature, as well as approximately 12 million pairs of simulated interactions between functional iORs and pheromones. We also built four online tools, iORPDB, iInteraction, iModelTM, and iOdorTool, to easily retrieve and visualize the 3D structures and interactions. iORbase can help greatly improve the experimental efficiency and success rate, identify new insecticide targets, or develop electronic nose technology. This study will shed light on the olfactory recognition mechanism and evolutionary characteristics from the perspectives of omics and macroevolution. This article is protected by copyright. All rights reserved.

Iron–sulfur (Fe–S) clusters play important roles in electron transfer, metabolic and biosynthetic reactions, and the regulation of gene expression. Understanding the biogenesis of Fe–S clusters is therefore relevant to many fields. In the complex process of Fe–S protein formation, the A-type assembly protein (ATAP) family, which consists of several subfamilies, plays an essential role in Fe–S cluster formation and transfer and is highly conserved across the tree of life. However, the taxonomic distribution, motif compositions, and the evolutionary history of the ATAP subfamilies are not well understood. To address these problems, our study investigated the taxonomic distribution of 321 species from a broad cross-section of taxa. Then, we identified common and specific motifs in multiple ATAP subfamilies to explain the functional conservation and nonredundancy of the ATAPs, and a novel, essential motif was found in Eumetazoa IscA1, which has a newly found magnetic function. Finally, we used phylogenetic analytical methods to reconstruct the evolution history of this family. Our results show that two types of ErpA proteins (nonproteobacteria-type ErpA1 and proteobacteria-type ErpA2) exist in bacteria. The ATAP family, consisting of seven subfamilies, can be further classified into two types of ATAPs. Type-I ATAPs include IscA, SufA, HesB, ErpA1, and IscA1, with an ErpA1-like gene as their last common ancestor, whereas type-II ATAPs consist of ErpA2 and IscA2, duplicated from an ErpA2-like gene. During the mitochondrial endosymbiosis, IscA became IscA1 in eukaryotes and ErpA2 became IscA2 in eukaryotes, respectively.

Background and Objective Due to the synergistic effects of drugs, drug combination is one of the effective approaches for treating complex diseases. However, the identification of drug combinations by dose-response methods is still costly. It is promising to develop supervised learning-based approaches to predict potential drug combinations on a large scale. Nevertheless, these approaches have the inadequate utilization of heterogeneous features, which causes the loss of information useful to classification. Moreover, they have an intrinsic bias, because they assume unknown drug pairs as non-combinations, of which some could be real drug combinations in practice. Methods To address above issues, this work first designs a two-layer multiple classifier system (TLMCS) to effectively integrate heterogeneous features involving anatomical therapeutic chemical codes of drugs, drug-drug interactions, drug-target interactions, gene ontology of drug targets, and side effects. To avoid the bias caused by labelling unknown samples as negative, it then utilizes the one-class support vector machines, (which requires no negative instance and only labels approved drug combinations as positive instances), as the member classifiers in TLMCS. Last, both a 10-fold cross validation (10-CV) and a novel prediction are performed to validate the performance of TLMCS. Results The comparison with three state-of-the-art approaches under 10-CV exhibits the superiority of TLMCS, which achieves the area under the receiver operating characteristic curve = 0.824 and the area under the precision-recall curve = 0.372. Moreover, the experiment under the novel prediction demonstrates its ability, where 9 out of the top-20 predicted combinative drug pairs are validated by checking the published literature. Furthermore, for each of the newly-validated drug combinations, this work analyses the combining mode of the member drugs and investigates their relationship in terms of drug targeting pathways. Conclusions The proposed TLMCS provides an effective framework to integrate those heterogeneous features and is trained by only positive samples such that the bias of taking unknown drug pairs as negative samples can be avoided. Furthermore, its results in the novel prediction reveal five types of drug combinations and three types of drug relationships in terms of pathways.

Large gradient high magnetic field (LG-HMF) is a powerful tool to study the effects of altered gravity on organisms. In our study, a platform for the long-term culture of aquatic organisms was designed based on a special superconducting magnet with an LG-HMF, which can provide three apparent gravity levels (µ g, 1 g, and 2 g), along with a control condition on the ground. Planarians, Dugesia japonica, were head-amputated and cultured for 5 days in a platform for head reconstruction. After planarian head regeneration, all samples were taken out from the superconducting magnet for a behavioral test under geomagnetic field and normal gravity conditions. To analyze differences among the four groups, four aspects of the planarians were considered, including head regeneration rate, phototaxis response, locomotor velocity, and righting behavior. Data showed that there was no significant difference in the planarian head regeneration rate under simulated altered gravity. According to statistical analysis of the behavioral test, all of the groups had normal functioning of the phototaxis response, while the planarians that underwent head reconstruction under the microgravity environment had significantly slower locomotor velocity and spent more time in righting behavior. Furthermore, histological staining and immunohistochemistry results helped us reveal that the locomotor system of planarians was affected by the simulated microgravity environment. We further demonstrated that the circular muscle of the planarians was weakened (hematoxylin and eosin staining), and the epithelial cilia of the planarians were reduced (anti-acetylated tubulin staining) under the simulated microgravity environment. Bioelectromagnetics. 2018;39:428-440. © 2018 Wiley Periodicals, Inc.

It is important to design insecticides having both low drug resistance and less undesirable toxicity for desert locust control. Specific GPCRs of Schistocerca gregaria, especially β-adrenergic-like octopamine receptor (SgOctβR), can be considered as its potential effective insecticide targets. However, either the unavailability of SgOctβR's structure or the inadequate capability of its sequence lead the development of insecticide for Schistocerca gregaria meets its plateau. To relax this difficulty, this paper develops a promising progressive structure simulation from SgOctβR's sequence, to its predicted structure of SgOctβR in vacuum, to its conformation as well as its complex with endogenous ligand octopamine in a solvent-membrane system. The combined approach of multiple sequence alignment, static structural characterization, and dynamic process of conformational change during binding octopamine reveal three important aspects. The first one is the characterization of SgOctβR's active pocket, including the attending secondary structure elements, its hydrophobic residues and nonpolar surface. The second one is the interaction with octopamine, especially the involved hydrogen bonds and an aromatic stacking of pi-pi interactions. The third one is the potential binding sites, including six highly conserved residues and one highly variable residue for locust insecticide design. This work is definitely helpful for the further structure-based drug design for efficient and eco-friendly insecticides, as well as site-directed mutagenesis biochemical research of SgOctβR.

Breast cancer (BC) and prostate cancer (PC) are the second most common malignant tumors in women and men in western countries, respectively. The risks of death are 14% for BC and 9% for PC. Abnormal estrogen and androgen levels are related to carcinogenesis of the breast and prostate. Estradiol stimulates cancer development in BC. The effect of estrogen on PC is concentration-dependent, and estrogen can regulate androgen production, further affecting PC. Estrogen can also increase the risk of androgen-induced PC. Androgen has dual effects on BC via different metabolic pathways, and the role of the androgen receptor (AR) in BC also depends on cell subtype and downstream target genes. Androgen and AR can stimulate both primary PC and castration-resistant PC. Understanding the mechanisms of the effects of estrogen and androgen on BC and PC may help us to improve curative BC and PC treatment strategies.

The pygmy grasshopper Tetrix japonica is a common insect distributed throughout the world, and it has the potential for use in studies of body colour polymorphism, genomics and the biology of Tetrigoidea (Insecta: Orthoptera). However, limited biological information is available for this insect. Here, we conducted a de novo transcriptome study of adult and larval T. japonica to provide a better understanding of its gene expression and develop genomic resources for future work. We sequenced and explored the characteristics of the de novo transcriptome of T. japonica using Illumina HiSeq 2000 platform. A total of 107 608 206 paired-end clean reads were assembled into 61 141 unigenes using the trinity software; the mean unigene size was 771 bp, and the N50 length was 1238 bp. A total of 29 225 unigenes were functionally annotated to the NCBI nonredundant protein sequences (Nr), NCBI nonredundant nucleotide sequences (Nt), a manually annotated and reviewed protein sequence database (Swiss-Prot), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. A large number of putative genes that are potentially involved in pigment pathways, juvenile hormone (JH) metabolism and signalling pathways were identified in the T. japonica transcriptome. Additionally, 165 769 and 156 796 putative single nucleotide polymorphisms occurred in the adult and larvae transcriptomes, respectively, and a total of 3162 simple sequence repeats were detected in this assembly. This comprehensive transcriptomic data for T. japonica will provide a usable resource for gene predictions, signalling pathway investigations and molecular marker development for this species and other pygmy grasshoppers.

The successful crystallization of proteins is important because their molecular three-dimensional structures can be obtained through X-ray diffraction when in their crystalline form. Investigation of the crystallization process is beneficial for this purpose. We have reported that protein crystallization is sensitive to audible sound, which is commonly present but is often ignored. Here we investigate the effect of audible sound parameters, especially frequency, on a protein crystallization. We show a significant facilitation of protein crystallization using 5000 Hz audible sound, possible mechanism was also tried to be clarified. Suitably controlled audible sound can be beneficial for promoting protein crystallization. Therefore, audible sound can be used as a simple tool to promote protein crystallization. In addition, the processing of other types of materials may also be affected by audible sound.

Crystallisation of proteins is usually achieved with the help of chemical agents. Because there are few general guidelines in determining what agents will help to crystallise a specific protein, suitable crystallisation agents are often found via exhaustive trial-and-error tests by mixing many chemical agents (the collection of which is called a crystallisation screening kit) one-by-one with the protein. Currently, many commercially available crystallisation screening kits have been developed and utilised in practical crystallisation screen experiments. However, information regarding the design of new screening kits has yet to be expanded using a large amount of experimental data. Here, we show the step-by-step design processes of a polyethylene glycol-based screening kit. It was found that the screening performance could be improved by modifying the crystallisation screening kits according to the accumulated data (such as those in the Biological Macromolecule Crystallisation Database (BMCD)), the screening test results and existing knowledge. The screening kit designed in this paper can be used for practical protein crystallisation screen experiments and the method can be used in the design of other crystallisation screening kits.

Large gradient high magnetic field (LG-HMF) is a powerful tool to study the effects of altered gravity on organisms. In our study, a platform for the long-term culture of aquatic organisms was designed based on a special superconducting magnet with an LG-HMF, which can provide three apparent gravity levels (µ g, 1 g, and 2 g), along with a control condition on the ground. Planarians, Dugesia japonica, were head-amputated and cultured for 5 days in a platform for head reconstruction. After planarian head regeneration, all samples were taken out from the superconducting magnet for a behavioral test under geomagnetic field and normal gravity conditions. To analyze differences among the four groups, four aspects of the planarians were considered, including head regeneration rate, phototaxis response, locomotor velocity, and righting behavior. Data showed that there was no significant difference in the planarian head regeneration rate under simulated altered gravity. According to statistical analysis of the behavioral test, all of the groups had normal functioning of the phototaxis response, while the planarians that underwent head reconstruction under the microgravity environment had significantly slower locomotor velocity and spent more time in righting behavior. Furthermore, histological staining and immunohistochemistry results helped us reveal that the locomotor system of planarians was affected by the simulated microgravity environment. We further demonstrated that the circular muscle of the planarians was weakened (hematoxylin and eosin staining), and the epithelial cilia of the planarians were reduced (anti-acetylated tubulin staining) under the simulated microgravity environment. Bioelectromagnetics. 2018;39:428-440. © 2018 Wiley Periodicals, Inc.

The pH of a solution is an important parameter in crystallization that needs to be controlled in order to ensure success. The actual pH of the crystallization droplet is determined by the combined contribution of the buffers in the screening and protein solutions, although the contribution of the latter to the pH is often ignored. In this study, the effects of the buffer and protein solution pH values on the results of screening are systematically investigated. It was found that these parameters significantly affected the results and thus the following strategy for the selection of appropriate pH values is proposed: (i) when screening with only one protein solution, the pH should be as low, as high or as divergent from the pI as possible for a basic, acidic or neutral protein, respectively, within its stable pH range; (ii) when screening with two protein solutions, the pH values should be well separated from one another; and (iii) when multiple pH values are utilized, an even distribution of pH values is the best approach to increase the success rate of crystallization.

The gradual desiccation method (GDM) is a modification of the vapor diffusion method for protein crystallization screening. This method can dramatically increase the chances of obtaining protein crystals and is therefore potentially useful for practical protein crystallization screening. However, it is troublesome to prepare the desiccant for the GDM because each of the 96 desiccants must be of the same mass. Repeated manual weighing of the desiccant (at least 96 times for one plate) to obtain the same amount is required, and manual distribution of the weighed desiccants to the respective reservoir wells is also necessary. These procedures require a considerable amount of labor and thus lower the efficiency of the screening process. Additionally, they reduce the applicability of this method in routine protein crystallization screening. To solve this problem, a high-throughput method is proposed, which involves dispensing an aqueous solution of salts (a combination of CoCl2and AlCl3) into a droplet array (8 × 12, corresponding to the arrangement in a standard crystallization plate) on a piece of tape, then drying this array to obtain the final desiccant array. Simply covering and sealing this desiccant array over the crystallization droplets in the crystallization plate can give a perfect vapor diffusion screen. With this method, the labor and automation requirements of the GDM will be comparable to those of the conventional vapor diffusion method; furthermore, the amount of the desiccant can be easily and accurately controlled, allowing the GDM to be applied in daily protein crystallization screening.

Background There has been paid more and more attention to supervised classification models in the area of predicting drug-target interactions (DTIs). However, in terms of classification, unavoidable missing DTIs in data would cause three issues which have not yet been addressed appropriately by former approaches. Directly labeled as negatives (non-DTIs), missing DTIs increase the confusion of positives (DTIs) and negatives, aggravate the imbalance between few positives and many negatives, and are usually discriminated as highly-scored false positives, which influence the existing measures sharply. Results Under the framework of local classification model (LCM), this work focuses on the scenario of predicting how possibly a new drug interacts with known targets. To address the first two issues, two strategies, Spy and Super-target, are introduced accordingly and further integrated to form a two-layer LCM. In the bottom layer, Spy-based local classifiers for protein targets are built by positives, as well as reliable negatives identified among unlabeled drug-target pairs. In the top layer, regular local classifiers specific to super-targets are built with more positives generated by grouping similar targets and their interactions. Furthermore, to handle the third issue, an additional performance measure, Coverage, is presented for assessing DTI prediction. The experiments based on benchmark datasets are finally performed under five-fold cross validation of drugs to evaluate this approach. The main findings are concluded as follows. (1) Both two individual strategies and their combination are effective to missing DTIs, and the combination wins the best. (2) Having the advantages of less confusing decision boundary at the bottom layer and less biased decision boundary at the top layer, our two-layer LCM outperforms two former approaches. (3) Coverage is more robust to missing interactions than other measures and is able to evaluate how far one needs to go down the list of targets to cover all the proper targets of a drug. Conclusions Proposing two strategies and one performance measure, this work has addressed the issues derived from missing interactions, which cause confusing and biased decision boundaries in classifiers, as well as the inappropriate measure of predicting performance, in the scenario of predicting interactions between new drugs and known targets.

Recombinant expression of proteins has become an indispensable tool in modern day research. The large yields of recombinantly expressed proteins accelerate the structural and functional characterization of proteins. Nevertheless, there are literature reported that the recombinant proteins show some differences in structure and function as compared with the native ones. Now there have been more than 100,000 structures (from both recombinant and native sources) publicly available in the Protein Data Bank (PDB) archive, which makes it possible to investigate if there exist any proteins in the RCSB PDB archive that have identical sequence but have some difference in structures. In this paper, we present the results of a systematic comparative study of the 3D structures of identical naturally purified versus recombinantly expressed proteins. The structural data and sequence information of the proteins were mined from the RCSB PDB archive. The combinatorial extension (CE), FATCAT-flexible and TM-Align methods were employed to align the protein structures. The root-mean-square distance (RMSD), TM-score, P-value, Z-score, secondary structural elements and hydrogen bonds were used to assess the structure similarity. A thorough analysis of the PDB archive generated five-hundred-seventeen pairs of native and recombinant proteins that have identical sequence. There were no pairs of proteins that had the same sequence and significantly different structural fold, which support the hypothesis that expression in a heterologous host usually could fold correctly into their native forms.

Background: The grasshopper Shirakiacris shirakii is an important agricultural pest and feeds mainly on gramineous plants, thereby causing economic damage to a wide range of crops. However, genomic information on this species is extremely limited thus far, and transcriptome data relevant to insecticide resistance and pest control are also not available. Methods: The transcriptome of S. shirakii was sequenced using the Illumina HiSeq platform, and we de novo assembled the transcriptome. Results: Its sequencing produced a total of 105,408,878 clean reads, and the de novo assembly revealed 74,657 unigenes with an average length of 680 bp and N50 of 1057 bp. A total of 28,173 unigenes were annotated for the NCBI non-redundant protein sequences (Nr), NCBI non-redundant nucleotide sequences (Nt), a manually-annotated and reviewed protein sequence database (Swiss-Prot), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Based on the Nr annotation results, we manually identified 79 unigenes encoding cytochrome P450 monooxygenases (P450s), 36 unigenes encoding carboxylesterases (CarEs) and 36 unigenes encoding glutathione S-transferases (GSTs) in S. shirakii. Core RNAi components relevant to miroRNA, siRNA and piRNA pathways, including Pasha, Loquacious, Argonaute-1, Argonaute-2, Argonaute-3, Zucchini, Aubergine, enhanced RNAi-1 and Piwi, were expressed in S. shirakii. We also identified five unigenes that were homologous to the Sid-1 gene. In addition, the analysis of differential gene expressions revealed that a total of 19,764 unigenes were up-regulated and 4185 unigenes were down-regulated in larvae. In total, we predicted 7504 simple sequence repeats (SSRs) from 74,657 unigenes. Conclusions: The comprehensive de novo transcriptomic data of S. shirakii will offer a series of valuable molecular resources for better studying insecticide resistance, RNAi and molecular marker discovery in the transcriptome.

We investigated the effect of paramagnetic salts (NiCl2, CoCl2, and MnCl2) on the magnetic orientation of hen-egg white lysozyme (HEWL) crystals at different pHs. Multiple orientation responses of the crystals to magnetic fields were discovered when NiCl2 and CoCl2 were used as the crystallization agents (the c-axis and the ⟨110⟩ orientations for NiCl2 solution, and the c-axis, the a-axis and the ⟨110⟩ orientations for CoCl2 solution). Only the normal c-axis orientation was found when MnCl2 was used as the crystallization agent. The multiple orientation responses were sensitive to the variations in the pH. These phenomena are discussed in the context of the incorporation of paramagnetic cations into lysozyme. Although anions affect the crystallization of lysozyme, the effect of cations on the crystallization of lysozyme has been considered marginal. This study reveals that cations can also exhibit profound effects on the crystallization of lysozyme.

Temperature is generally considered as an important factor in protein crystallization. Such is true because crystals usually grow at a preferable temperature in a certain crystallization solution. If a nonsuitable temperature is used, the solution will not yield crystals. However, it is difficult to decide the best temperature suited for screening the crystallization condition of proteins. In this study, it was found out that, compared to constant temperature, a variation in a reasonable range can result in a more efficient crystallization screening. Using the Sparse Matrix Screen with the screening kit Index, this study tested nine commercially available proteins and proved that, compared to the conventional constant temperature strategy, a varying temperature strategy can actually increase the possibility of obtaining crystals. Consequently, the cycling temperature strategy (CTS) is then proposed to be utilized in most screening tasks when the suitable crystallization temperature is unknown.

Magnetic field has been found to be able to improve the quality of some protein crystals; containerless condition is considered to be beneficial for growing good-quality crystals. Nevertheless, there has been no report on combination of these two conditions for protein crystallization. In this paper, crystallization and dissolution of protein crystals in a levitated containerless droplet in a strong magnetic field has been successfully achieved. New phenomena were observed for both crystallization and dissolution processes.

Determination of protein 3-dimensional structure offers very important information in biology researches, especially for understanding protein functions and redundant drug design. The X-ray crystallography is still the main technique for protein structure determination. Obtaining protein crystals is an essential procedure after protein purification in this technique. However, there is only 42% of soluble purified proteins yield crystals by statistics. Experimental verification of protein crystallizability is relatively expensive and time-consuming. Thus it is desired to predict the protein crystallizability by a computational method before starting the experiment. In this paper, combined with our own efforts, some successful in silico methods to predict the protein crystallizability are reviewed.

Predicting drug-target interaction DTI by computational methods has gained more and more concerns in both drug discovery and repositioning. However, several inherent difficulties in DTI data have not yet been addressed appropriately, including the powerless prediction of interactions for new drugs and/or new targets, the biased predicting model derived from imbalanced samples and the inadequate solution to missing interactions and multiple similarities. Moreover, assessed on inappropriate scenarios, existing methods may generate over-optimistic predictions. In this paper, we predict the potential interactions between new drugs and new targets based on pairwise K-nearest neighbor. With lower computational complexity, the proposed approach is able to obtain the less biased prediction and to relax the difficulty caused by missing interactions. Moreover, we develop a strategy to automatically select the best among multiple similarities to train classifiers. Based on four benchmark datasets, the effectiveness of our approach is demonstrated by an appropriate cross validation.

The sequences of the mitochondrial 16S rRNA gene of 16 Oedipodidae species were amplified and sequenced. All sequences were aligned and analyzed and the phyloge- netic relationships were inferred. The properties of 16S gene in Oedipodidae showed typical patterns of many insects such as a high A+T content and variable distance-dependent transition/transversion ratios. The 0.2 weight for sites of loops may be advisable for phylogeny reconstruction using the maximum parsimony method. The phylogenetic analy- sis results do not support the current subfamily classification systems of Oedipodidae. Bryodemellinae and Bryodeminae are closely related and should be merged as one subfamily. The status of Oedipodinae and Locustinae is also problematic.

High-quality crystals are key to obtaining accurate three-dimensional structures of proteins using X-ray diffraction techniques. However, obtaining such protein crystals is often a challenge. Several containerless crystallization techniques have been reported to have the ability to improve crystal quality, but it is unknown which is the most favourable way to grow high-quality protein crystals. In this paper, a quality comparison of protein crystals which were grown under three containerless conditions provided by diamagnetic levitation, silicone oil and agarose gel was conducted. A control experiment on a vessel wall was also simultaneously carried out. Seven different proteins were crystallized under the four conditions, and the crystal quality was assessed in terms of the resolution limit, the mosaicity and theRmerge. It was found that the crystals grown under the three containerless conditions demonstrated better morphology than those of the control. X-ray diffraction data indicated that the quality of the crystals grown under the three containerless conditions was better than that of the control. Of the three containerless crystallization techniques, the diamagnetic levitation technique exhibited the best performance in enhancing crystal quality. This paper is to our knowledge the first report of improvement of crystal quality using a diamagnetic levitation technique. Crystals obtained from agarose gel demonstrated the second best improvement in crystal quality. The study indicated that the diamagnetic levitation technique is indeed a favourable method for growing high-quality protein crystals, and its utilization is thus potentially useful in practical efforts to obtain well diffracting protein crystals.

The contact angle is an important parameter that is essential for studying interfacial phenomena. The contact angle can be measured using commercially available instruments. However, these well-developed instruments may not function or may be unsuitable for use in some special environments. A simulated microgravity generated by a large gradient magnetic field is such an environment in which the current measurement instruments cannot be installed. To measure the contact angle in this environment, new tools must be designed and manufactured to be compatible with the size and physical environment. In this study, we report the development and construction of a new setup that was specifically designed for use in a strong magnetic field to measure the contact angle between a levitated droplet and a solid surface. The application of the setup in a large gradient magnetic field was tested, and the contact angles were readily measured.

A high-field superconducting magnet can provide both high-magnetic fields and large-field gradients, which can be used as a special environment for research or practical applications in materials processing, life science studies, physical and chemical reactions, etc. To make full use of a superconducting magnet, shared instruments (the operating platform, sample holders, temperature controller, and observation system) must be prepared as prerequisites. This paper introduces the design of a set of sample holders and a temperature controller in detail with an emphasis on validating the performance of the force and temperature sensors in the high-magnetic field.

Drug abuse harms people's health and lead to a series of economic, social and political problems. However, the problems of physical damage, physical dependence and withdrawal syndrome caused by drug abuse still exist. Planarians have been a new animal experimental model in vivo for neuropharmacology, because they possess a primitive central nervous system and neurotransmitter systems similarly to mammalians. In addition, they have the advantage of convenience and low cost and no ethics problems compared with mammalian models. The advantages of planarian as experimental model in vivo and the progress of the investigations of drug addiction mechanism in planarians are summarized, and the trends in this field are discussed in this review.

As the most widely utilized technique to determine the 3-dimensional structure of protein molecules, X-ray crystallography can provide structure of the highest resolution among the developed techniques. The resolution obtained via X-ray crystallography is known to be influenced by many factors, such as the crystal quality, diffraction techniques, and X-ray sources, etc. In this paper, the authors found that the protein sequence could also be one of the factors. We extracted information of the resolution and the sequence of proteins from the Protein Data Bank (PDB), classified the proteins into different clusters according to the sequence similarity, and statistically analyzed the relationship between the sequence similarity and the best resolution obtained. The results showed that there was a pronounced correlation between the sequence similarity and the obtained resolution. These results indicate that protein structure itself is one variable that may affect resolution when X-ray crystallography is used.

Table 2 of the article by Caoet al.[(2013),Acta Cryst.D69, 1901–1910] is corrected.

Containerless processing of materials is considered beneficial for obtaining high quality products due to the elimination of the detrimental effects coming from the contact with container walls. Many containerless processing methods are realized by levitation techniques. This paper describes a containerless levitation setup that utilized the magnetization force generated in a gradient magnetic field. It comprises a levitation unit, a temperature control unit, and a real-time observation unit. Known volume of liquid diamagnetic samples can be levitated in the levitation chamber, the temperature of which is controlled using the temperature control unit. The evolution of the levitated sample is observed in real time using the observation unit. With this setup, containerless processing of liquid such as crystal growth from solution can be realized in a well-controlled manner. Since the levitation is achieved using a superconducting magnet, experiments requiring long duration time such as protein crystallization and simulation of space environment for living system can be easily succeeded.