Search

Monolayer nanosheets of zirconium phosphate in aqueous suspension exhibit short-range repulsion and long-range attraction, producing, at overall volume fractions larger than about half a percent, phase separation into higher-concentration liquid crystal and lower-concentration isotropic regions. At high concentrations, this phase separation takes the form of an emulsion of condensed, liquid-crystalline droplets, which anneal to form lens-shaped tactoids. These tactoids provide an opportunity to study the liquid crystal ordering of inorganic nanosheets in the limit of large shape anisotropy (diameter/thickness~400) and high packing fraction (volume fraction ≳ 70%). The internal liquid crystal structure of the tactoids remains nematic even under conditions that would usually favor ordering into lamellar smectics. Local lamellar ordering is suggested by short-range, smectic-like layer correlations, but a full transition into a smectic phase appears to be inhibited by the nanosheet edges, which act as a perturbative population of dislocation loops in the system of layers. Under conditions of thermal equilibrium, the nanoplates organize positionally to enable bend deformation of the director, a hallmark of the nematic phase and its principal distinction from the smectic, where bend must be expelled. [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND: Transcatheter arterial chemoembolization (TACE) is thought to prevent recurrence of hepatocellular carcinoma (HCC), but its efficacy is a matter of controversy. OBJECTIVES: We investigated the effect of preventive TACE on the tumor, nodes, metastasis (TNM) classification in cases of stage II HCC (T2N0M0) after R0 resection. DESIGN AND SETTING: Case-control study conducted in a tertiary-level public hospital. METHODS: We analyzed recurrence rates and mortality rates over time for 250 consecutive cases of HCC in TNM classification cases of stage II HCC (T2N0M0) after R0 resection. These cases were divided into patients who underwent TACE (TACE+) and presented microvascular invasion (MVI+; n = 80); TACE+ but did not present MVI (MIV−; n = 100); MVI+ but did not undergo TACE (TACE−, n = 30); and TACE−/MVI− (n = 40). RESULTS: MVI+ patients in the TACE+ group had significantly lower recurrence rates and mortality rates at one, two and three years than those in the TACE- group (all P < 0.05). Among MVI- patients, the TACE+ group did not have significantly lower recurrence rates and mortality rates at one, two and three years than the TACE- group (all P > 0.05). Regardless of whether TACE was performed or not, MVI− patients had significantly lower recurrence rates and mortality rates at two and three years after their procedures than did MVI+ patients (all P < 0.05). CONCLUSION: Recurrence rates and mortality rates for MVI+ patients were significantly higher than for MVI− patients, beyond the first year after TACE. Postoperative adjuvant TACE may be beneficial for HCC patients with MVI.

The twist-bend nematic liquid crystal phase is a three-dimensional fluid in which achiral bent molecules spontaneously form an orientationally ordered, macroscopically chiral, heliconical winding of a ten nanometer-scale pitch in the absence of positional ordering. Here, the structure of the twist-bend phase of the bent dimer CB7CB and its mixtures with 5CB is characterized, revealing a hidden invariance of the self-assembly of the twist-bend structure of CB7CB, such that over a wide range of concentrations and temperatures, the helix pitch and cone angle change as if the ground state for a pitch of the TB helix is an inextensible heliconical ribbon along the contour formed by following the local molecular long axis (the director). Remarkably, the distance along the length for a single turn of this helix is given by 2πRmol, where Rmol is the radius of bend curvature of a single all-trans CB7CB molecule. This relationship emerges from frustrated steric packing due to the bent molecular shape: space in the fluid that is hard to fill attracts the most flexible molecular subcomponents, a theme of nanosegregation that generates self-assembled, oligomer-like correlations of interlocking bent molecules in the form of a brickwork-like tiling of pairs of molecular strands into duplex double-helical chains. At higher temperatures in the twist-bend phase, the cone angle is small, the director contour is nearly along the helix axis z, and the duplex chains are sequences of biaxial elements formed by overlapping half-molecule pairs, with an approximately 45° rotation of the biaxis between each such element along the chain. [ABSTRACT FROM AUTHOR]

RFID technology has become popular in many applications; however, most of the RFID products lack security related functionality due to the hardware limitation of the low-cost RFID tags. In this paper, we propose a lightweight mutual authentication protocol adopting error correction code for RFID. Besides, we also propose an advanced version of our protocol to provide key updating. Based on the secrecy of shared keys, the reader and the tag can establish a mutual authenticity relationship. Further analysis of the protocol showed that it also satisfies integrity, forward secrecy, anonymity, and untraceability. Compared with other lightweight protocols, the proposed protocol provides stronger resistance to tracing attacks, compromising attacks and replay attacks. We also compare our protocol with previous works in terms of performance.

Biomolecular networks are often assumed to be scale-free hierarchical networks. The weighted gene co-expression network analysis (WGCNA) treats gene co-expression networks as undirected scale-free hierarchical weighted networks. The WGCNA R software package uses an Adjacency Matrix to store a network, next calculates the topological overlap matrix (TOM), and then identifies the modules (sub-networks), where each module is assumed to be associated with a certain biological function. The most time-consuming step of WGCNA is to calculate TOM from the Adjacency Matrix in a single thread. In this paper, the single-threaded algorithm of the TOM has been changed into a multi-threaded algorithm (the parameters are the default values of WGCNA). In the multi-threaded algorithm, Rcpp was used to make R call a C++ function, and then C++ used OpenMP to start multiple threads to calculate TOM from the Adjacency Matrix. On shared-memory MultiProcessor systems, the calculation time decreases as the number of CPU cores increases. The algorithm of this paper can promote the application of WGCNA on large data sets, and help other research fields to identify sub-networks in undirected scale-free hierarchical weighted networks. The source codes and usage are available at https://github.com/do-somethings-haha/multi-threaded_calculate_unsigned_TOM_from_unsigned_or_signed_Adjacency_Matrix_of_WGCNA. [ABSTRACT FROM AUTHOR]

In this work, Gd-based coordination polymer (GdCP) hollow spheres have been synthesized by a general, facile and template-free solvothermal strategy. The products were well characterized and analyzed. Results indicate that the uniform hollow nanospheres have diameters of 160-260 nm. Influential factors such as reaction temperature, time, and dosage of reagents on the morphology and size of the GdCP hollow spheres have been systematically investigated. An Ostwald ripening mechanism coupled with a self-assembly process for the hollow structures formation was proposed based on a series of time-dependent experiments. Furthermore, after doping with Yb/Er ions, characteristic red upconversion emission from F→I of Er was realized under 980 nm NIR irradiation. [ABSTRACT FROM AUTHOR]

In some liquid crystal (LC) mixtures of bent-core host molecules that form helical nanofilaments (HNFs) and chiral, rod-shaped molecular guests, the spontaneous chirality of the HNFs is not influenced by the guest handedness. In other mixtures, the filaments become homochiral, responding to the handedness of the guest. We show that the important distinction between these two behaviours is the solubility of the guest material in the HNF phase. In our experiments, chiral LC mesogens doped into the HNF phase result in an enantiomeric imbalance and sometimes change the phase sequence on cooling from the isotropic melt. [ABSTRACT FROM PUBLISHER]

As DNA exhibits persistent structures with dimensions that exceed the range of their intermolecular forces, solid-state DNA undergoes thermal degradation at elevated temperatures. Therefore, the realization of solvent-free DNA fluids, including liquid crystals and liquids, still remains a significant challenge. To address this intriguing issue, we demonstrate that combining DNA with suitable cationic surfactants, followed by dehydration, can be a simple generic scheme for producing these solvent-free DNA fluid systems. In the anhydrous smectic liquid crystalline phase, DNA sublayers are intercalated between aliphatic hydrocarbon sublayers. The lengths of the DNA and surfactant are found to be extremely important in tuning the physical properties of the fluids. Stable liquid-crystalline and liquid phases are obtained in the −20 °C to 200 °C temperature range without thermal degradation of the DNA. Thus, a new type of DNA-based soft biomaterial has been achieved, which will promote the study and application of DNA in a much broader context. [ABSTRACT FROM AUTHOR]

RFID technology has become popular in many applications; however, most of the RFID products lack security related functionality due to the hardware limitation of the low-cost RFID tags. In this paper, we propose a lightweight mutual authentication protocol adopting error correction code for RFID. Besides, we also propose an advanced version of our protocol to provide key updating. Based on the secrecy of shared keys, the reader and the tag can establish a mutual authenticity relationship. Further analysis of the protocol showed that it also satisfies integrity, forward secrecy, anonymity, and untraceability. Compared with other lightweight protocols, the proposed protocol provides stronger resistance to tracing attacks, compromising attacks and replay attacks. We also compare our protocol with previous works in terms of performance. [ABSTRACT FROM AUTHOR]

Liver fibrosis refers to a reversible event of repair and reconstruction following injury due to various etiologies, and its continuous development will lead to cirrhosis and liver cancer. Abnormal alterations in intestinal microbiota can hasten the development of hepatic fibrosis and damage. Veronicastrum latifolium (Hemsl.) Yamazaki (VLY) is a classic drug applied extensively for managing acute and chronic hepatitis, liver cirrhosis and ascites in ethnic minority areas of Guizhou Province, China, which possesses broad-spectrum pharmacological activities. In view of the crucial role of intestinal microbiota in the development of liver fibrosis, the present study attempted to investigate the effects of VLY aqueous extract on ameliorating CCl 4 -elicited liver fibrosis in mice and on intestinal microbiota and to explore its possible mechanism. Phytochemical analysis showed that VLY water extract contained a variety of components, particularly rich in organic acids and their derivatives, flavonoids, phenolic acids, nucleotides and their derivatives, carbohydrates and other compounds. VLY water extract remarkably alleviated CCl 4 -induced liver damage and fibrosis in mice, improved liver histology, and improved liver function abnormalities. VLY water extract also inhibited the activation of hepatic stellate cells and invasion of intrahepatic inflammatory cells. Additionally, sequencing the 16 s rDNA gene revealed that VLY water extract changed the intestinal microbiota composition in liver fibrotic mice. It elevated the Firmicutes/Bacteroidota ratio and enriched the relative Lactobacillus richness, which is capable of mitigating fibrosis and inflammation in impaired liver. In summary, through modulation of inflammation and intestinal microbiota, VLY water extract can reduce the CCl 4 -elicited liver fibrosis. [Display omitted] [ABSTRACT FROM AUTHOR]

The chiral, heliconical (twist-bend) nematic ground state is reported in an achiral, rigid, bent-core mesogen (UD68). Similar to the nematic twist-bend (/VTB) phase observed in bent molecular dimers, the NTB phase of UD68 forms macroscopic, smecticlike focal-conic textures and exhibits nanoscale, periodic modulation with no associated modulation of the electron density, i.e., without a detectable lamellar x-ray reflection peak. The NTB helical pitch is pTB~ 14 nm. When an electric field is applied normal to the helix axis, a weak electroclinic effect is observed, revealing 50-μm-scale left- and right-handed domains in a chiral conglomerate. [ABSTRACT FROM AUTHOR]

We demonstrate the strong dependency of the isotropic-nematic (I-N) transition of discotic suspensions on the aspect ratio (f = thickness/diameter) via control of the sizes of pristine ZrP crystals and subsequent exfoliation to monolayers. The size fractionation of the I-N transition facilitates the analysis of the effect of polydispersity. A systematic variation in the aspect ratio in the low aspect ratio region (0.001 < § < 0.01) showed that the I-N transition volume fraction increases witíi the aspect ratio in agreement with computer simulations. It was found that the transition volume fractions scale with aspect ratio $i,N = nj|1-36±o-'") where the prefactor m strongly depends on size polydispersity for ¡fa but does not depend on size polydispersity for i with \ and ¡fa being the volume fractions of the isotropic and the nematic phases on the cloud curves, respectively. [ABSTRACT FROM AUTHOR]

Salvia miltiorrhiza (Labiatae) is an important medicinal plant in traditional Chinese medicine. Tanshinones are one of the main active components of S. miltiorrhiza . It has been found that the intraspecific variation of S. miltiorrhiza is relatively large and the content of tanshinones in its roots of different varieties is also relatively different. To investigate the molecular mechanisms that responsible for the differences among these varieties, the tanshinones content was determined and comparative transcriptomics analysis was carried out during the tanshinones accumulation stage. A total of 52,216 unigenes were obtained from the transcriptome by RNA sequencing among which 23,369 genes were differentially expressed among different varieties, and 2,016 genes including 18 diterpenoid biosynthesis-related genes were differentially expressed during the tanshinones accumulation stage. Functional categorization of the differentially expressed genes (DEGs) among these varieties revealed that the pathway related to photosynthesis, oxidative phosphorylation, secondary metabolite biosynthesis, diterpenoid biosynthesis, terpenoid backbone biosynthesis, sesquiterpenoid and triterpenoid biosynthesis are the most differentially regulated processes in these varieties. The six tanshinone components in these varieties showed different dynamic changes in tanshinone accumulation stage. In addition, combined with the analysis of the dynamic changes, 277 DEGs (including one dehydrogenase, three CYP450 and 24 transcription factors belonging to 12 transcription factor families) related to the accumulation of tanshinones components were obtained. Furthermore, the KEGG pathway enrichment analysis of these 277 DEGs suggested that there might be an interconnection between the primary metabolic processes, signaling processes and the accumulation of tanshinones components. This study expands the vision of intraspecific variation and gene regulation mechanism of secondary metabolite biosynthesis pathways in medicinal plants from the "omics" perspective., Competing Interests: The authors declare that they have no competing interests., (© 2021 Zhou et al.)

Background: Transcatheter arterial chemoembolization (TACE) is thought to prevent recurrence of hepatocellular carcinoma (HCC), but its efficacy is a matter of controversy., Objectives: We investigated the effect of preventive TACE on the tumor, nodes, metastasis (TNM) classification in cases of stage II HCC (T2N0M0) after R0 resection., Design and Setting: Case-control study conducted in a tertiary-level public hospital., Methods: We analyzed recurrence rates and mortality rates over time for 250 consecutive cases of HCC in TNM classification cases of stage II HCC (T2N0M0) after R0 resection. These cases were divided into patients who underwent TACE (TACE+) and presented microvascular invasion (MVI+; n = 80); TACE+ but did not present MVI (MIV-; n = 100); MVI+ but did not undergo TACE (TACE-, n = 30); and TACE-/MVI- (n = 40)., Results: MVI+ patients in the TACE+ group had significantly lower recurrence rates and mortality rates at one, two and three years than those in the TACE- group (all P < 0.05). Among MVI- patients, the TACE+ group did not have significantly lower recurrence rates and mortality rates at one, two and three years than the TACE- group (all P > 0.05). Regardless of whether TACE was performed or not, MVI- patients had significantly lower recurrence rates and mortality rates at two and three years after their procedures than did MVI+ patients (all P < 0.05)., Conclusion: Recurrence rates and mortality rates for MVI+ patients were significantly higher than for MVI- patients, beyond the first year after TACE. Postoperative adjuvant TACE may be beneficial for HCC patients with MVI.

Resonant x-ray scattering shows that the bulk structure of the twist-bend liquid crystal phase, recently discovered in bent molecular dimers, has spatial periodicity without electron density modulation, indicating a lattice-free heliconical nematic precession of orientation that has helical glide symmetry. In situ study of the bulk helix texture of the dimer CB7CB shows an elastically confined temperature-dependent minimum helix pitch, but a remarkable elastic softness of pitch in response to dilative stresses. Scattering from the helix is not detectable in the higher temperature nematic phase.