Multidisciplinary management based on clinical nursing pathway model for the treatment of hypertensive intracerebral hemorrhage: A randomized controlled trial.

Objective: To explore the effectiveness of multidisciplinary management based on a clinical nursing pathway model for the treatment of hypertensive intracerebral hemorrhage (HICH).

Methods: A total of 124 patients with HICH admitted to our hospital between February 2021 and June 2023 were selected as research subjects in this randomized, controlled, unblinded study. They were divided into Control-group and Study-group using a random number table method, with 62 cases in each group.

Multi-Indicator Intelligent Monitoring of Clinical Observations to Reduce Cesarean Section.

In order to analyze multi-index monitoring and the effect of reducing cesarean section, this paper selects March 2018 and March 2019 in two obstetrics and gynecology hospitals, referred to as hospital A and hospital B. As research objects, 313 pregnant women were divided into multi-index group and conventional group, while analyzing various indicators of each group of cesarean collection. The results show that the total CNAXE rate was 48.

Dynamics of the base of ribosomal A-site finger revealed by molecular dynamics simulations and Cryo-EM.

Helix 38 (H38) of the large ribosomal subunit, with a length of 110 A, reaches the small subunit through intersubunit bridge B1a. Previous cryo-EM studies revealed that the tip of H38 moves by more than 10 A from the non-ratcheted to the ratcheted state of the ribosome while mutational studies implicated a key role of flexible H38 in attenuation of translocation and in dynamical signaling between ribosomal functional centers. We investigate a region including the elbow-shaped kink-turn (Kt-38) in the Haloarcula marismortui archaeal ribosome, and equivalently positioned elbows in three eubacterial species, located at the H38 base.

Determination of signal-to-noise ratios and spectral SNRs in cryo-EM low-dose imaging of molecules.

Attempts to develop efficient classification approaches to the problem of heterogeneity in single-particle reconstruction of macromolecules require phantom data with realistic noise models. We have estimated the signal-to-noise ratios and spectral signal-to-noise ratios for three steps in the electron microscopic image formation from data obtained experimentally. An important result is that structural noise, i.

SPIDER image processing for single-particle reconstruction of biological macromolecules from electron micrographs.

This protocol describes the reconstruction of biological molecules from the electron micrographs of single particles. Computation here is performed using the image-processing software SPIDER and can be managed using a graphical user interface, termed the SPIDER Reconstruction Engine. Two approaches are described to obtain an initial reconstruction: random-conical tilt and common lines.

The process of mRNA-tRNA translocation.

In the elongation cycle of translation, translocation is the process that advances the mRNA-tRNA moiety on the ribosome, to allow the next codon to move into the decoding center. New results obtained by cryoelectron microscopy, interpreted in the light of x-ray structures and kinetic data, allow us to develop a model of the molecular events during translocation.

RF3 induces ribosomal conformational changes responsible for dissociation of class I release factors.

During translation termination, class II release factor RF3 binds to the ribosome to promote rapid dissociation of a class I release factor (RF) in a GTP-dependent manner. We present the crystal structure of E. coli RF3*GDP, which has a three-domain architecture strikingly similar to the structure of EF-Tu*GTP.

Disentangling conformational states of macromolecules in 3D-EM through likelihood optimization.

Although three-dimensional electron microscopy (3D-EM) permits structural characterization of macromolecular assemblies in distinct functional states, the inability to classify projections from structurally heterogeneous samples has severely limited its application. We present a maximum likelihood-based classification method that does not depend on prior knowledge about the structural variability, and demonstrate its effectiveness for two macromolecular assemblies with different types of conformational variability: the Escherichia coli ribosome and Simian virus 40 (SV40) large T-antigen.

Unsupervised classification of single particles by cluster tracking in multi-dimensional space.

In cryo-electron microscopy (cryo-EM) single-particle reconstruction, the heterogeneity of two-dimensional projection image data resulting from the co-existence of different conformational or ligand binding states of a macromolecular complex remains a major obstacle as it impairs the validity of reconstructed density maps and limits the progress toward higher resolution. Classification of cryo-EM data according to the different conformations is difficult because of the coexistence of multiple orientations in a single dataset. Here, we present an unsupervised classification method, termed cluster tracking, which utilizes the continuity in multi-dimensional space induced by angular adjacency of projections in large datasets.

Interactions of the release factor RF1 with the ribosome as revealed by cryo-EM.

In eubacteria, termination of translation is signaled by any one of the stop codons UAA, UAG, and UGA moving into the ribosomal A site. Two release factors, RF1 and RF2, recognize and bind to the stop codons with different affinities and trigger the hydrolysis of the ester bond that links the polypeptide with the P-site tRNA. Cryo-electron microscopy (cryo-EM) results obtained in this study show that ribosome-bound RF1 is in an open conformation, unlike the closed conformation observed in the crystal structure of the free factor, allowing its simultaneous access to both the decoding center and the peptidyl-transferase center.

The structure of the 80S ribosome from Trypanosoma cruzi reveals unique rRNA components.

We present analysis, by cryo-electron microscopy and single-particle reconstruction, of the structure of the 80S ribosome from Trypanosoma cruzi, the kinetoplastid protozoan pathogen that causes Chagas disease. The density map of the T. cruzi 80S ribosome shows the phylogenetically conserved eukaryotic rRNA core structure, together with distinctive structural features in both the small and large subunits.

Molding atomic structures into intermediate-resolution cryo-EM density maps of ribosomal complexes using real-space refinement.

Real-space refinement has been previously introduced as a flexible fitting method to interpret medium-resolution cryo-EM density maps in terms of atomic structures. In this way, conformational changes related to functional processes can be analyzed on the molecular level. In the application of the technique to the ribosome, quasiatomic models have been derived that have advanced our understanding of translocation.

The role of tRNA as a molecular spring in decoding, accommodation, and peptidyl transfer.

Translation is the process by which the genetic information contained in mRNA is used to link amino acids in a predetermined sequential order into a polypeptide chain, which then folds into a protein. Transfer RNAs (tRNAs) are the adapter molecules designed to provide the "lookup" from codons to amino acids. Cryo-EM has provided evidence that the ribosome, as a molecular machine, undergoes many structural changes during translation.

Dynamics of EF-G interaction with the ribosome explored by classification of a heterogeneous cryo-EM dataset.

A method of supervised classification using two available structure templates was applied to investigate the possible heterogeneity existing in a large cryo-EM dataset of an Escherichia coli 70S ribosome-EF-G complex. Two subpopulations showing the ribosome in distinct conformational states, related by a ratchet-like rotation of the 30S subunit with respect to the 50S subunit, were extracted from the original dataset. The possible presence of additional intermediate states is discussed.

Study of the structural dynamics of the E coli 70S ribosome using real-space refinement.

Cryo-EM density maps showing the 70S ribosome of E. coli in two different functional states related by a ratchet-like motion were analyzed using real-space refinement. Comparison of the two resulting atomic models shows that the ribosome changes from a compact structure to a looser one, coupled with the rearrangement of many of the proteins.

An assay for local quality in cryo-electron micrographs of single particles.

High quality of the cryo-electron micrographs is of crucial importance for the success of single particle three-dimensional reconstruction methods. In analyzing some micrographs from cryo-electron microscopy specimens, we found an extraordinary variability, within the same micrograph, in the appearance of particles. We developed a method for analyzing the variability of local image quality, using correspondence analysis of local power spectra.