Zygospore development of Spirogyra (Charophyta) investigated by serial block-face scanning electron microscopy and 3D reconstructions

Sexual reproduction of Zygnematophyceae by conjugation is a less investigated topic due to the difficulties of the induction of this process and zygospore ripening under laboratory conditions. For this study, we collected field sampled zygospores of Spirogyra mirabilis and three additional Spirogyra strains in Austria and Greece. Serial block-face scanning electron microscopy was performed on high pressure frozen and freeze substituted zygospores and 3D reconstructions were generated, allowing a comprehensive insight into the process of zygospore maturation, involving storage compound and organelle rearrangements. Chloroplasts are drastically changed, while young stages contain both parental chloroplasts, the male chloroplasts are aborted and reorganised as 'secondary vacuoles' which initially contain plastoglobules and remnants of thylakoid membranes. The originally large pyrenoids and the volume of starch granules is significantly reduced during maturation (young: 8 ± 5 µm³, mature: 0.2 ± 0.2 µm³). In contrast, lipid droplets (LDs) increase significantly in number upon zygospore maturation, while simultaneously getting smaller (young: 21 ± 18 µm³, mature: 0.1 ± 0.2 and 0.5 ± 0.9 µm³). Only in S. mirabilis the LD volume increases (34 ± 29 µm³), occupying ~50% of the zygospore volume. Mature zygospores contain barite crystals as confirmed by Raman spectroscopy with a size of 0.02 - 0.05 µm³. The initially thin zygospore cell wall (~0.5 µm endospore, ~0.8 µm exospore) increases in thickness and develops a distinct, electron dense mesospore, which has a reticulate appearance (~1.4 µm) in Spirogyra sp. from Greece. The exo- and endospore show cellulose microfibrils in a helicoidal pattern. In the denser endospore, pitch angles of the microfibril layers were calculated: ~18 ± 3° in S. mirabilis, ~20 ± 3° in Spirogyra sp. from Austria and ~38 ± 8° in Spirogyra sp. from Greece. Overall this study gives new insights into Spirogyra sp. zygospore development, crucial for survival during dry periods and dispersal of this genus.

In vitro efficacy of Er:YAG laser-activated irrigation versus passive ultrasonic irrigation and sonic-powered irrigation for treating multispecies biofilms in artificial grooves and dentinal tubules: an SEM and CLSM study

BACKGROUND

Multispecies biofilms located in the anatomical intricacies of the root canal system remain the greatest challenge in root canal disinfection. The efficacy of Er:YAG laser-activated irrigation techniques for treating multispecies biofilms in these hard-to-reach areas has not been proved. The objective of this laboratory study was to evaluate the effectiveness of two Er:YAG laser-activated irrigation techniques, namely, photon-induced photoacoustic streaming (PIPS) and shock wave-enhanced emission photoacoustic streaming (SWEEPS), in treating multispecies biofilms within apical artificial grooves and dentinal tubules, in comparison with conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI), and sonic-powered irrigation (EDDY). Two types of multispecies root canal biofilm models were established in combination with two assessment methods using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) with the aim to obtain more meaningful results.

METHODS

Ninety extracted human single-rooted premolars were chosen for two multispecies biofilm models. Each tooth was longitudinally split into two halves. In the first model, a deep narrow groove was created in the apical segment of the canal wall. After cultivating a mixed bacterial biofilm for 4 weeks, the split halves were reassembled and subjected to five irrigation techniques: CNI, PUI, EDD, PIPS, and SWEEPS. The residual biofilms inside and outside the groove in Model 1 were analyzed using SEM. For Model 2, the specimens were split longitudinally once more to evaluate the percentage of killed bacteria in the dentinal tubules across different canal sections (apical, middle, and coronal thirds) using CLSM. One-way analysis of variance and post hoc multiple comparisons were used to assess the antibiofilm efficacy of the 5 irrigation techniques.

RESULTS

Robust biofilm growth was observed in all negative controls after 4 weeks. In Model 1, within each group, significantly fewer bacteria remained outside the groove than inside the groove (P < 0.05). SWEEPS, PIPS and EDDY had significantly greater biofilm removal efficacy than CNI and PUI, both from the outside and inside the groove (P < 0.05). Although SWEEPS was more effective than both PIPS and EDDY at removing biofilms inside the groove (P < 0.05), there were no significant differences among these methods outside the groove (P > 0.05). In Model 2, SWEEPS and EDDY exhibited superior bacterial killing efficacy within the dentinal tubules, followed by PIPS, PUI, and CNI (P < 0.05).

CONCLUSION

Er:YAG laser-activated irrigation techniques, along with EDDY, demonstrated significant antibiofilm efficacy in apical artificial grooves and dentinal tubules, areas that are typically challenging to access.

[Effectiveness of the central government-funded echinococcosis control programme in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022]

OBJECTIVE

To evaluate the effectiveness of the central government-funded echinococcosis control programme in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, so as to provide insights into echinococcosis control.

METHODS

Administrative villages were sampled using a multi-stage cluster random sampling method from Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, and all residents at ages of 12 years and older in the sampled villages were screened for echinococcosis, and schools were sampled using a cluster sampling method, and all children at ages of 12 years and older in the sampled schools were screened for echinococcosis. Domestic dogs were sampled using a systematic random sampling method, and one domestic dog stool sample was collected from each household. Stray dog stool samples were collected outside the villages, and Echinococcus coproantigens were detected using enzyme-linked immunosorbent assay in domestic and stray dogs. In addition, echinococcosis was screened in sheep and cattle in designated slaughterhouses in Tianzhu Tibetan Autonomous County. The trends in the prevalence of echinococcosis in humans and livestock and the positive rate of Echinococcus coproantigens in dogs were examined with the Cochran-Armitage trend test. In addition, individuals screened for echinococcosis were randomly sampled from 2007 to 2022 for survey on the awareness of echinococcosis control knowledge.

RESULTS

A total of 290 356 person-times were screened for echinococcosis among residents at ages of 12 years and older in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, with 1 094 residents detected with cystic echinococcosis, and the detection of echinococcosis appeared a tendency towards a gradual decline over years (χ2 = 358.602, P < 0.001). A total of 32 931 person-times were screened for echinococcosis among children at ages of 12 years and older in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, with 296 children detected with echinococcosis, and the detection of echinococcosis appeared a tendency towards a gradual decline over years (χ2 = 267.673, P < 0.001). A total of 33 230 domestic dog stool samples were tested for Echinococcus coproantigens in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, with 1 777 Echinococcus coproantigens-positive samples tested, and the positive rate of Echinococcus coproantigens appeared a tendency towards a decline in domestic dogs over years (χ2 = 2 210.428, P < 0.001), while the positive rate of Echinococcus coproantigens showed a tendency towards a rise in domestic animals from 2016 to 2022 (χ2 = 37.745, P < 0.001). The positive rate of Echinococcus coproantigens remained relatively stable in stray dogs in Tianzhu Tibetan Autonomous County, Gansu Province from 2019 to 2022 (χ2 = 0.315, P = 0.575). A total of 10 973 sheep were screened for echinococcosis in Tianzhu Tibetan Autonomous County from 2007 to 2022, with 334 sheep detected with echinococcosis, and the detection of echinococcosis appeared a tendency towards a decline in sheep over years (χ2 = 53.579, P < 0.001); however, there was no significant change in the detection of echinococcosis during the period from 2015 through 2022 (χ2 = 1.520, P = 0.218). A total of 2 400 cattle were screened for echinococcosis in Tianzhu Tibetan Autonomous County from 2017 to 2022, with 231 cattle detected with echinococcosis, and the detection of echinococcosis showed a tendency towards a decline over years (χ2 = 5.579, P < 0.05). The awareness of echinococcosis control knowledge increased from 44.37% in 2007 to 94.00% in 2022 among residents at ages of 12 years and older and from 52.50% in 2007 to 92.50% in 2022 among children at ages of 12 years and older in Tianzhu Tibetan Autonomous County, respectively.

CONCLUSIONS

There has been a reduction in the detection of echinococcosis in humans and domestic animals and the positive rate of Echinococcus coproantigens in dogs and a rise in the awareness of the echinococcosis control knowledge following the implementation of the central government-funded echinococcosis control programme in Tianzhu Tibetan Autonomous County, Gansu Province; however, integrated echinococcosis control measures are still required for further control of the prevalence of echinococcosis.

Prognostic Value of Tumor Volume Reduction during Radiotherapy in Patients with Locally Advanced Cervical Cancer in Different Risk Groups

PURPOSE/OBJECTIVE(S)

To evaluate the risk factors of patients with locally advanced cervical cancer (LACC) undergoing radical radiotherapy (with or without concurrent chemotherapy) and to assess the prognostic value of tumor volume regression (TVR) based on magnetic resonance imaging (MRI) in different risk groups.

MATERIALS/METHODS

A retrospective analysis was performed on 176 individuals diagnosed with stage IIA-IVA cervical cancer (CC) who underwent radical intensity-modulated radiotherapy in our center between January 2012 and December 2020. The tumor volume before radiotherapy (TVp) and before brachytherapy (TVmid) were evaluated based on three-dimensional MRI images, TVR = (TVp -TVmid)/TVp × 100%. Kaplan-Meier curves were used to assess patient's overall survival (OS) and progression-free survival (PFS). Prognostic factors were identified using Cox proportional hazards models.

RESULTS

For the entire cohort, patients with TVR ≥ 94% had better 5-year OS (82.7% vs 49.8%, p<0.001) and 5-year PFS (82.5% vs 51.1%, p<0.001) compared to TVR < 94%. Patients with TVR ≥ 94% were more likely to receive concurrent chemoradiotherapy (CCRT) than those with TVR < 94% (70.1% vs 40.5%, p<0.05). Among patients undergoing CCRT, those with a TVR ≥ 94% had a better prognosis than those with a TVR < 94%. However, among patients who received RT alone, those with TVR ≥ 94% had better PFS but no statistically significant difference in OS. Likewise, among patients with CYFRA21-1 < 7.7 ng/ml, patients with TVR ≥ 94% had a better prognosis. However, TVR was not a prognostic factor in patients with CYFRA21-1 ≥ 7.7 ng/ml. Both CYFRA21-1 (OS, PFS interaction, p<0.001) and FIGO stage (PFS interaction, p = 0.035) were found to significantly impact predictive effects of TVR.

CONCLUSION

In LACC patients with CRYFA21-1 < 7.7 ng/ml who received CCRT, TVR was an important prognostic factor. However, in patients with CRYFA21-1 ≥ 7.7 ng/ml who received RT alone, the prognostic value of TVR needs to be further explored.

Preclinical validation of the advection diffusion flow estimation method using computational patient specific coronary tree phantoms

Coronary computed tomography angiography (CCTA) does not allow the quantification of reduced blood flow due to coronary artery disease (CAD). In response, numerical methods based on the CCTA image have been developed to compute coronary blood flow and assess the impact of disease. However to compute blood flow in the coronary arteries, numerical methods require specification of boundary conditions that are difficult to estimate accurately in a patient-specific manner. We describe herein a new noninvasive flow estimation method, called Advection Diffusion Flow Estimation (ADFE), to compute coronary artery flow from CCTA to use as boundary conditions for numerical models of coronary blood flow. ADFE uses image contrast variation along the tree-like structure to estimate flow in each vessel. For validating this method we used patient specific software phantoms on which the transport of contrast was simulated. This controlled validation setting enables a direct comparison between estimated flow and actual flow and a detailed investigation of factors affecting accuracy. A total of 10 CCTA image data sets were processed to extract all necessary information for simulating contrast transport. A spectral element method solver was used for computing the ground truth simulations with high accuracy. On this data set, the ADFE method showed a high correlation coefficient of 0.998 between estimated flow and the ground truth flow together with an average relative error of only 1 % . Comparing the ADFE method with the best method currently available (TAFE) for image-based blood flow estimation, which showed a correlation coefficient of 0.752 and average error of 20 % , it can be concluded that the ADFE method has the potential to significantly improve the quantification of coronary artery blood flow derived from contrast gradients in CCTA images.

[The design method of the digital sequential tooth-sectioning guide for the extraction of mandibular impacted third molars]

Objective: To explore a method for digitally designing and fabricating a sequential tooth-sectioning guide that can assist in the extraction of mandibular horizontal impacted third molars, preliminarily evaluate its feasibility and provide a reference for clinical application. Methods: Twenty patients with mandibular low level impacted third molars who visited the Department of General Dentistry, Peking University School and Hospital of Stomatology from March 2021 to January 2022 were selected. Cone-beam CT showed direct contact between the roots and mandibular canal, and full range impressions of the patients' intraoral teeth were taken and optical scans of the dental model were performed. The patients' cone-beam CT data and optical scan data were reconstructed in three dimensions, anatomical structure extraction, registration fusion, and the design of the structure of the guide (including crown-sectioning guide and root-sectioning guide) by Mimics 24.0, Geomagic Wrap 2021, and Magics 21.0 software, and then the titanium guide was three dimension printed, and the guide was tried on the dental model. After confirmation, the guide was used to assist the dentist in the operation. We observed whether the guide was in place, the number of tooth splitting, the matching of tooth splitting with the preoperative design, the operation time, and whether there were any complications. Results: In this study, 20 sectioning guides were successfully printed, all of them were well fitted in the patients' mouth, the average number of section was 3.4 times, the tooth parts was better matched with the preoperative design, and the average operative time of the guides was (29.2±9.8) minutes without complications such as perforation of the bone cortex. Conclusions: The use of sequential sectioning guides to assist in the extraction of mandibular impacted third molars was initially validated to accurately replicate the preoperative sectioning design, and is expected to provide a digital solution to improve surgical precision and ensure safety. Further studies with larger sample sizes are needed to evaluate its accuracy and safety.

[Preliminary evaluation of the trueness of 5 chairside 3D facial scanning techniques]

OBJECTIVE

To quantitatively evaluate the trueness of five chairside three-dimensional facial scanning techniques, and to provide reference for the application of oral clinical diagnosis and treatment.

METHODS

The three-dimensional facial data of the subjects were collected by the traditional professional three-dimensional facial scanner Face Scan, which was used as the reference data of this study. Four kinds of portable three-dimensional facial scanners (including Space Spider, LEO, EVA and DS-FScan) and iPhone Ⅹ mobile phone (Bellus3D facial scanning APP) were used to collect three-dimensional facial data from the subjects. In Geomagic Studio 2013 software, through data registration, deviation analysis and other functions, the overall three-dimensional deviation and facial partition three-dimensional deviation of the above five chairside three-dimensional facial scanning technologies were calculated, and their trueness performance evaluated. Scanning time was recorded during the scanning process, and the subject's comfort was scored by visual analogue scale(VAS). The scanning efficiency and patient acceptance of the five three-dimensional facial scanning techniques were evaluated.

RESULTS

DS-FScan had the smallest mean overall and mean partition three-dimensional deviation between the test data and the reference data, which were 0.334 mm and 0.329 mm, respectively. The iPhone Ⅹ mobile phone had the largest mean overall and mean partition three-dimensional deviation between the test data and the reference data, which were 0.483 mm and 0.497 mm, respectively. The detailed features of the three-dimensional facial data obtained by Space Spider were the best. The iPhone Ⅹ mobile phone had the highest scanning efficiency and the highest acceptance by the subject. The average scanning time of the iPhone Ⅹ mobile phone was 14 s, and the VAS score of the subjects' scanning comfort was 9 points.

CONCLUSION

Among the five chairside three-dimensional face scanning technologies, the trueness of the scan data of the four portable devices had no significant difference, and they were all better than the iPhone Ⅹ mobile phone scan. The subject with the iPhone Ⅹ scanning technology had the best expe-rience.

3D (x-y-t) Raman imaging of tomato fruit cuticle: Microchemistry during development

The cuticle is a protective extracellular matrix that covers the above-ground epidermis of land plants. Here, we studied the cuticle of tomato (Solanum lycopersicum L.) fruits in situ using confocal Raman microscopy. Microsections from cuticles isolated at different developmental stages were scanned to visualize cuticle components with a spatial resolution of 342 nm by univariate and multivariate data analysis. Three main components, cutin, polysaccharides, and aromatics, were identified, with the latter exhibiting the strongest Raman scattering intensity. Phenolic acids and flavonoids were differentiated within the cuticle, and three schematic cuticle models were identified during development. Phenolic acids were found across the entire cuticle at the earliest stage of development, i.e. during the formation of the procuticle layer. Based on a mixture analysis with reference component spectra, the phenolic acids were identified as mainly esterified p-coumaric acid together with free p-hydroxybenzoic acid. During the cell expansion period of growth, phenolic acids accumulated in an outermost layer of the cuticle and in the middle region of the pegs. In these stages of development, cellulose and pectin were detected next to the inner cuticle region, close to the epidermal cell where flavonoid impregnation started during ripening. In the first ripening stage, chalconaringenin was observed, while methoxylated chalcones were chosen by the algorithm to fit the mature cuticle spectra. The colocation of carbohydrates, esterified p-coumaric acid, and methoxylated chalconaringenin suggests that the latter two link polysaccharide and cutin domains. Elucidating the different distribution of aromatics within the cuticle, suggests important functions: (1) overall impregnation conferring mechanical and thermal functions (2) the outermost phenolic acid layer displaying UV-B protection of the plant tissue.

Frozen mountain pine needles: The endodermis discriminates between the ice-containing central tissue and the ice-free fully functional mesophyll

Conifer (Pinaceae) needles are the most frost-hardy leaves. During needle freezing, the exceptional leaf anatomy, where an endodermis separates the mesophyll from the vascular tissue, could have consequences for ice management and photosynthesis. The eco-physiological importance of needle freezing behaviour was evaluated based on the measured natural freezing strain at the alpine treeline. Ice localisation and cellular responses to ice were investigated in mountain pine needles by cryo-microscopic techniques. Their consequences for photosynthetic activity were assessed by gas exchange measurements. The freezing response was related to the microchemistry of cell walls investigated by Raman microscopy. In frozen needles, ice was confined to the central vascular cylinder bordered by the endodermis. The endodermal cell walls were lignified. In the ice-free mesophyll, cells showed no freeze-dehydration and were found photosynthetically active. Mesophyll cells had lignified tangential cell walls, which adds rigidity. Ice barriers in mountain pine needles seem to be realised by a specific lignification patterning of cell walls. This, additionally, impedes freeze-dehydration of mesophyll cells and enables gas exchange of frozen needles. At the treeline, where freezing is a dominant environmental factor, the elaborate needle freezing pattern appears of ecological importance.

DriverMP enables improved identification of cancer driver genes

BACKGROUND

Cancer is widely regarded as a complex disease primarily driven by genetic mutations. A critical concern and significant obstacle lies in discerning driver genes amid an extensive array of passenger genes.

FINDINGS

We present a new method termed DriverMP for effectively prioritizing altered genes on a cancer-type level by considering mutated gene pairs. It is designed to first apply nonsilent somatic mutation data, protein‒protein interaction network data, and differential gene expression data to prioritize mutated gene pairs, and then individual mutated genes are prioritized based on prioritized mutated gene pairs. Application of this method in 10 cancer datasets from The Cancer Genome Atlas demonstrated its great improvements over all the compared state-of-the-art methods in identifying known driver genes. Then, a comprehensive analysis demonstrated the reliability of the novel driver genes that are strongly supported by clinical experiments, disease enrichment, or biological pathway analysis.

CONCLUSIONS

The new method, DriverMP, which is able to identify driver genes by effectively integrating the advantages of multiple kinds of cancer data, is available at https://github.com/LiuYangyangSDU/DriverMP. In addition, we have developed a novel driver gene database for 10 cancer types and an online service that can be freely accessed without registration for users. The DriverMP method, the database of novel drivers, and the user-friendly online server are expected to contribute to new diagnostic and therapeutic opportunities for cancers.

[Research progress of mesenchymal stem cell in the treatment of diabetic bladder dysfunction]

Diabetic bladder dysfunction (DBD) is a common complication in the lower urinary tract of diabetes. In recent years, mesenchymal stem cell (MSC) have broad application prospects in the treatment of DBD. MSC can migrate to damaged bladder tissue and differentiate into various cell types, such as urothelial cells, myofibroblasts, smooth muscle cells and nerve cells, promote bladder tissue repair and regeneration through paracrine effects. In addition, MSC also intervene in the pathological process of DBD, reverse disease progression, and restore partial bladder function through immune regulation, improvement of oxidative stress, and regulation of blood glucose. At present, the treatment of DBD with MSC is limited to preclinical animal experiments, clinical research and application should be pursued further.

The walnut shell network: 3D visualisation of symplastic and apoplastic transport routes in sclerenchyma tissue

High symplastic connectivity via pits was linked to the lignification of the developing walnut shell. With maturation, this network lessened, whereas apoplastic intercellular space remained and became relevant for shell drying. The shell of the walnut (Juglans regia) sclerifies within several weeks. This fast secondary cell wall thickening and lignification of the shell tissue might need metabolites from the supporting husk tissue. To reveal the transport capacity of the walnut shell tissue and its connection to the husk, we visualised the symplastic and apoplastic transport routes during shell development by serial block face-SEM and 3D reconstruction. We found an extensive network of pit channels connecting the cells within the shell tissue, but even more towards the husk tissue. Each pit channel ended in a pit field, which was occupied by multiple plasmodesmata passing through the middle lamella. During shell development, secondary cell wall formation progressed towards the interior of the cell, leaving active pit channels open. In contrast, pit channels, which had no plasmodesmata connection to a neighbouring cell, got filled by cellulose layers from the inner cell wall lamellae. A comparison with other nut species showed that an extended network during sclerification seemed to be linked to high cell wall lignification and that the connectivity between cells got reduced with maturation. In contrast, intercellular spaces between cells remained unchanged during the entire sclerification process, allowing air and water to flow through the walnut shell tissue when mature. The connectivity between inner tissue and environment was essential during shell drying in the last month of nut development to avoid mould formation. The findings highlight how connectivity and transport work in developing walnut shell tissue and how finally in the mature state these structures influence shell mechanics, permeability, conservation and germination.

Endocytic trafficking promotes vacuolar enlargements for fast cell expansion rates in plants

The vacuole has a space-filling function, allowing a particularly rapid plant cell expansion with very little increase in cytosolic content (Löfke et al., 2015; Scheuring et al., 2016; Dünser et al., 2019). Despite its importance for cell size determination in plants, very little is known about the mechanisms that define vacuolar size. Here, we show that the cellular and vacuolar size expansions are coordinated. By developing a pharmacological tool, we enabled the investigation of membrane delivery to the vacuole during cellular expansion. Our data reveal that endocytic membrane sorting from the plasma membrane to the vacuole is enhanced in the course of rapid root cell expansion. While this ‘compromise’ mechanism may theoretically at first decelerate cell surface enlargements, it fuels vacuolar expansion and, thereby, ensures the coordinated augmentation of vacuolar occupancy in dynamically expanding plant cells.

Biomimetic Immunosuppressive Exosomes that Inhibit Cytokine Storms Contribute to the Alleviation of Sepsis

Sepsis is a disease characterized by multiple organ failure caused by immune hyperactivation and cytokine storms. Studies have shown that the incidence of sepsis in melanoma patients is substantially lower compared to the general population. It is also observed that experimental tumor-bearing animals have high survival rates after sepsis induction, suggesting that tumors may suppress sepsis-associated immune overactivation, thereby alleviating sepsis. Based on the above-described findings, this work assesses whether tumor cells play an antisepsis role in mice through the secretion of exosomes. Analysis of exosome activity reveals that the induced exosomes (iExo) secreted by tumor cells following lipopolysaccharide (LPS) treatment improve sepsis to a greater extent than normal secretory exosomes. Further analysis reveals that iExo exert their protective effects mainly through seven key miRNAs. In vitro bionic simulation of exosomes is carried out using exosome mimics generated by loading the aforementioned microRNAs into hyaluronic acid-polyethylenimine nanoparticles. Exosome mimics at specific miRNA ratios alleviate sepsis in mice and cynomolgus monkeys, indicating that biomimetic simulation of tumor-suppressive exosomes may represent a promising therapeutic method for the treatment of sepsis and cytokine-storm-related conditions.

[Preliminary study on the method of automatically determining facial landmarks based on three-dimensional face template]

Objective: To explore the establishment of an efficient and automatic method to determine anatomical landmarks in three-dimensional (3D) facial data, and to evaluate the effectiveness of this method in determining landmarks. Methods: A total of 30 male patients with tooth defect or dentition defect (with good facial symmetry) who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from June to August 2021 were selected, and these participants' age was between 18-45 years. 3D facial data of patients was collected and the size normalization and overlap alignment were performed based on the Procrustes analysis algorithm. A 3D face average model was built in Geomagic Studio 2013 software, and a 3D face template was built through parametric processing. MeshLab 2020 software was used to determine the serial number information of 32 facial anatomical landmarks (10 midline landmarks and 22 bilateral landmarks). Five male patients with no mandibular deviation and 5 with mild mandibular deviation were selected from the Department of Orthodontics or Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from June to August 2021. 3D facial data of patients was collected as test data. Based on the 3D face template and the serial number information of the facial anatomical landmarks, the coordinates of 32 facial anatomical landmarks on the test data were automatically determined with the help of the MeshMonk non-rigid registration algorithm program, as the data for the template method to determine the landmarks. The positions of 32 facial anatomical landmarks on the test data were manually determined by the same attending physician, and the coordinates of the landmarks were recorded as the data for determining landmarks by the expert method. Calculated the distance value of the coordinates of facial anatomical landmarks between the template method and the expert method, as the landmark localization error, and evaluated the effect of the template method in determining the landmarks. Results: For 5 patients with no mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (1.65±1.19) mm, the landmark localization error of the midline facial anatomical landmarks was (1.19±0.45) mm, the landmark localization error of bilateral facial anatomical landmarks was (1.85±1.33) mm. For 5 patients with mild mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (2.55±2.22) mm, the landmark localization error of the midline facial anatomical landmarks was (1.85±1.13) mm, the landmark localization error of bilateral facial anatomical landmarks was (2.87±2.45) mm. Conclusions: The automatic determination method of facial anatomical landmarks proposed in this study has certain feasibility, and the determination effect of midline facial anatomical landmarks is better than that of bilateral facial anatomical landmarks. The effect of determining facial anatomical landmarks in patients without mandibular deviation is better than that in patients with mild mandibular deviation.

[Concept and mechanism innovations provide a sustainable driver for echinococcosis control in China]

China is one of the countries with the highest disease burden of echinococcosis in the world. China's progress in echinococcosis control started with limited scientific research projects, followed by nationwide epidemiological surveys, and then launched a national echinococcosis control programme on the basis of a pilot intervention project. During this process, science-based control and technological innovations have been integrated into echinococcosis control in China. The concept and mechanism innovations-based echinococcosis control models and successful experiences in highly endemic foci promote the sustainable echinococcosis control achievements in China. In addition, the joint echinococcosis prevention and control and sharing of successful experiences with other echinococcosis-endemic countries will provide China's wisdom, China's strategy and China's contributions to global echinococcosis control and the health of human beings.

[Investigation on population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province]

OBJECTIVE

To investigate the population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province.

METHODS

Rodents were captured using the mouse trap method in pastures from Batang Township and Longbao Township of Yushu City, Qinghai Province on May, August and October, 2018. The body weight and snout-vent length of all captured rodents were measured, and the species was identified according to the rodent morphology. Genomic DNA was extracted from rodent liver specimens and lesion specimens, and the mitochondrial cox1 gene of Echinococcus was amplified using PCR assay for identification of parasite species. In addition, the tissue specimens positive for PCR assay were sampled for pathological examinations. The prevalence of Echinococcus infections was estimated in rodents, and a phylogenetic tree was created based on Echinococcus cox1 gene sequences.

RESULTS

A total of 285 small rodents were captured, including 143 Ochotona curzoniae (50.2%), 141 Lasiopodomys fuscus (49.5%), and 1 Neodon irene (0.3%), and there was a remarkable variation in habitat selection among these three rodent species. The number of L. fuscus correlated positively with vegetation coverage (r = 0.350, P = 0.264), with the greatest number seen in August, and the number of O. curzoniae negatively with vegetation coverage (r = -0.371, P = 0.235), with the highest number seen in August and the lowest number in May. The female/male ratios of O. curzoniae and voles were 1:0.96 and 0.82:1, respectively. The body weight (r = 0.519, P < 0.01) and snout-vent length (r = 0.578, P < 0.01) of O. curzoniae showed a tendency towards a rise with month, while the body weight (r = -0.401, P < 0.01) and snout-vent length (r = -0.570, P < 0.01) of voles presented a tendency towards a reduction with month. No Echinococcus infection was detected in voles, while 2.1% prevalence of E. shiquicus infection was seen in O. curzoniae. Phylogenetic analysis revealed consistent sequences of cox1 gene from E. shiquicus in Yushu City of Qinghai Province and Shiqu County, Ganzi Tibetan Autonomous Prefecture of Sichuan Province.

CONCLUSIONS

The small rodents around the human settlement in Yushu City of Qinghai Province mainly include O. curzoniae and L. fuscus, with the greatest numbers seen in May and August, respectively. Following the concerted efforts for echinococcosis control, the prevalence of Echinococcus infections is low in small rodents around the human settlement in Yushu City; however, there is still a risk of echinococcosis transmission.

Twist and lock: nutshell structures for high strength and energy absorption

Nutshells achieve remarkable properties by optimizing structure and chemistry at different hierarchical levels. Probing nutshells from the cellular down to the nano- and molecular level by microchemical and nanomechanical imaging techniques reveals insights into nature's packing concepts. In walnut and pistachio shells, carbohydrate and lignin polymers assemble to form thick-walled puzzle cells, which interlock three-dimensionally and show high tissue strength. Pistachio additionally achieves high-energy absorption by numerous lobes interconnected via ball-joint-like structures. By contrast, the three times more lignified walnut shells show brittle LEGO-brick failure, often along the numerous pit channels. In both species, cell walls (CWs) show distinct lamellar structures. These lamellae involve a helicoidal arrangement of cellulose macrofibrils as a recurring motif. Between the two nutshell species, these lamellae show differences in thickness and pitch angle, which can explain the different mechanical properties on the nanolevel. Our in-depth study of the two nutshell tissues highlights the role of cell form and their interlocking as well as plant CW composition and structure for mechanical protection. Understanding these plant shell concepts might inspire biomimetic material developments as well as using walnut and pistachio shell waste as sustainable raw material in future applications.

Structural difference analysis of adult's intestinal flora basing on the 16S rDNA gene sequencing technology

OBJECTIVE

Through 16S rDNA technology, we aimed at separating adults aging 20-50 years old into a few groups and processing the high-throughput sequencing analysis, in order to explore the features and differences of intestinal flora in each age group in a microcosmic perspective.

PATIENTS AND METHODS

120 stool specimens were collected strictly in accordance with acceptance criteria and exclusion criteria. 49 subjects aging 20-29 years old (Group AGE1), 51 subjects aging 30-39 years old (Group AGE2), and 20 subjects aging 40-49 years old (Group AGE3) were divided into 3 groups. Bacteria DNA from fresh stool specimens of 3 groups were abstracted. Illumina MiSeq high-throughput sequencing platform was applied to process 16S rDNA sequencing in Area 338F_806R for intestinal flora detection. I-Sanger Bio-cloud platform was applied for the analysis of intestinal flora structure changes in phylum level and genus level.

RESULTS

Among the age of 20-50, with older age, the abundance of intestinal flora decreased among healthy adults more than 40 years old. In addition, the diversity and sample dispersion of intestinal flora is significantly different from people among 20-40 years old. The decrease ratio of Firmicutes/Bacteroidetes indicated that as the age grows, glucose tolerance might decrease. Comparing with people among 20-40 years old, the amount of Bifidobacterium and Eubacterium in people over 40 years old have significantly decreased. The decrease of Bifidobacterium and Eubacterium may increase the risks of cognitive impairment and lower the anti-inflammation and anti-cancer efficacy in human body, respectively. Subdoligranulum relates to poor metabolism and chronic inflammation and it happens more in people aged over 40 than young people who are among 20-40 years old.

CONCLUSIONS

There are differences in the intestinal flora of healthy adults aged 20-50. Effective intervention of the intestinal flora may play a role in delaying aging and preventing diseases.

A belt for the cell: cellulosic wall thickenings and their role in morphogenesis of the 3D puzzle cells in walnut shells

Walnut (Juglans regia) kernels are protected by a tough shell consisting of polylobate sclereids that interlock into a 3D puzzle. The shape transformations from isodiametric to lobed cells is well documented for 2D pavement cells, but not for 3D puzzle sclereids. Here, we study the morphogenesis of these cells by using a combination of different imaging techniques. Serial face-microtomy enabled us to reconstruct tissue growth of whole walnut fruits in 3D, and serial block face-scanning electron microscopy exposed cell shapes and their transformation in 3D during shell tissue development. In combination with Raman and fluorescence microscopy, we revealed multiple loops of cellulosic thickenings in cell walls, acting as stiff restrictions during cell growth and leading to the lobed cell shape. Our findings contribute to a better understanding of the 3D shape transformation of polylobate sclereids and the role of pectin and cellulose within this process.

[Study on the hospitalization cost and its influencing factors of imported malaria patients in Guangxi Zhuang Autonomous Region and Yunnan Province]

OBJECTIVE

To analyze the hospitalization cost and its influencing factors of imported malaria patients in Guangxi Zhuang Autonomous Region and Yunnan Province, so as to provide insights into the evaluation of the economic burden due to imported malaria, and the guiding of malaria control and the rational allocation of medical resources.

METHODS

The data pertaining to the hospitalization costs of imported malaria patients admitted to Shanglin County People's Hospital in Guangxi Zhuang Autonomous Region during the period from January 1 through December 31, 2019, and Tengchong Municipal People's Hospital in Yunnan Province from January 1, 2015 to December 31, 2019, were collected, and the epidemiological data of these imported malaria patients were extracted from the Information Management System for Parasitic Diseases Control and Prevention, China. The composition of the hospitalization expenses was analyzed using a descriptive method. In addition, the factors affecting the hospitalization expenses of imported malaria patients were identified using a univariate analysis and a recursive system model.

RESULTS

A total of 206 imported malaria patients were included in this study, including 194 men (94.17%) and 12 women (5.83%). The mean length of hospital stay was 5.00 days per patient and the median hospitalization expenses were 2 813.07 Yuan per time, in which the expenses for laboratory examinations were the highest (45.31%, 1 274.62/2 813.07). Univariate analysis showed that hospital (z = 5.43, P < 0.01), type of malaria (χ² = 34.86, P < 0.01) and type of payment (χ² = 7.72, P < 0.05) were factors affecting the hospitalization expenses of imported malaria patients. Recursion system modeling revealed that the total effects on hospitalization expenses of imported malaria patients included length of hospital stay (0.78), selection of hospital (0.34), basic medical insurance for urban and rural residents (0.19), new rural cooperative medical care (0.17), Plasmodium falciparum malaria (0.15), gender (0.11) and P. vivax malaria (0.09).

CONCLUSIONS

The hospitalization expenses of imported malaria patients are affected by multiple factors in Guangxi Zhuang Autonomous Region and Yunnan Province, in which the length of hospital stay is the most predominant influencing factor. A reduction in the length of hospital stay is effective to decrease the hospitalization expenses of imported malaria patients.

Oak wood drying: precipitation of crystalline ellagic acid leads to discoloration

Oak heartwood usually darkens during and after drying. This darkening can be heterogeneous, leaving noncolored areas in the wood board. These light discolorations have been linked to heterogeneous distribution of tannins, but compelling evidence on the microscale is lacking. In this study Raman and fluorescence microscopy revealed precipitations of crystalline ellagic acid, especially in the ray cells but also in lumina, cell corners and cell walls in the non-colored areas (NCA), which also had higher density. In these denser areas free water is longer present during drying and leads to accumulation of hydrolyzed tannins. When eventually falling dry, these tannins precipitate irreversible as non-colored ellagic acid and are not available for chemical reactions leading to darkening of the wood. Therefore, pronounced density fluctuations in wood boards require adjusting the drying and processing parameters so that water domains and ellagic acid precipitations are avoided during drying.

Topological Interlocking and Geometric Stiffening as Complementary Strategies for Strong Plant Shells

Many organisms encapsulate their embryos in hard, protective shells. While birds and reptiles largely rely on mineralized shells, plants often develop highly robust lignocellulosic shells. Despite the abundance of hard plant shells, particularly nutshells, it remains unclear which fundamental properties drive their mechanical stability. This multiscale analysis of six prominent (nut)shells (pine, pistachio, walnut, pecan, hazelnut, and macadamia) reveals geometric and structural strengthening mechanisms on the cellular and macroscopic length scales. The strongest tissues, found in walnut and pistachio, exploit the topological interlocking of 3D-puzzle cells and thereby outperform the fiber-reinforced structure of macadamia under tensile and compressive loading. On the macroscopic scale, strengthening occurs via an increased shell thickness, spherical shape, small size, and a lack of extended sutures. These functional interrelations suggest that simple geometric modifications are a powerful and resource-efficient strategy for plants to enhance the fracture resistance of entire shells and their tissues. Understanding the interplay between structure, geometry, and mechanics in hard plant shells provides new perspectives on the evolutionary diversification of hard seed coats, as well as insights for nutshell-based material applications.

Winter Nights during Summer Time: Stress Physiological Response to Ice and the Facilitation of Freezing Cytorrhysis by Elastic Cell Wall Components in the Leaves of a Nival Species

Ranunculus glacialis grows and reproduces successfully, although the snow-free time period is short (2-3 months) and night frosts are frequent. At a nival site (3185 m a.s.l.), we disentangled the interplay between the atmospheric temperature, leaf temperatures, and leaf freezing frequency to assess the actual strain. For a comprehensive understanding, the freezing behavior from the whole plant to the leaf and cellular level and its physiological after-effects as well as cell wall chemistry were studied. The atmospheric temperatures did not mirror the leaf temperatures, which could be 9.3 °C lower. Leaf freezing occurred even when the air temperature was above 0 °C. Ice nucleation at on average -2.6 °C started usually independently in each leaf, as the shoot is deep-seated in unfrozen soil. All the mesophyll cells were subjected to freezing cytorrhysis. Huge ice masses formed in the intercellular spaces of the spongy parenchyma. After thawing, photosynthesis was unaffected regardless of whether ice had formed. The cell walls were pectin-rich and triglycerides occurred, particularly in the spongy parenchyma. At high elevations, atmospheric temperatures fail to predict plant freezing. Shoot burial prevents ice spreading, specific tissue architecture enables ice management, and the flexibility of cell walls allows recurrent freezing cytorrhysis. The peculiar patterning of triglycerides close to ice rewards further investigation.

[Establishment of a recombinase-aided isothermal amplification assay for nucleic acid detection of Echinococcus multilocularis and its preliminary application]

OBJECTIVE

To establish a rapid nucleic acid detection technique for identification of Echinococcus multilocularis based on the recombinase aided isothermal amplification assay (RAA) and assess its diagnostic efficiency.

METHODS

The mitochondrial gene sequence of E. multilocularis (GenBank accession number: AB018440) was used as a target sequence. The primers were designed according to the RAA reaction principle and synthesized, and RAA was performed using the generated primers. E. multilocularis genomic DNA at various concentrations and the pMD19-T (Simple) vector containing various copies of the target gene fragment were amplified using RAA to evaluate its sensitivity for detection of E. multilocularis, and RAA was em- ployed to detect the genomic DNA of E. granulosus G1 genotype, Taenia saginata, T. asiatica, T. multiceps, Dipylidium caninum, Toxocara canis, Trichuris trichiura, Giardia lamblia, Fasciola hepatica, Paragonimus westermani, Fasciola gigantica and Clonorchis sinensis to evaluate its specificity. In addition, the optimized RAA was employed to detect nine tissue specimens of E. granulosus-infected animals, 3 fecal samples from E. granulosus-infected dogs and 2 fecal samples from field infected dogs to examine its reliability and feasibility.

RESULTS

The established RAA was able to detect the specific target gene fragment of E. multilocularis within 40 min. The lowest detect limit of RAA was 10 pg if E. multilocularis genomic DNA served as a template. If the re- combinant plasmid was used as a template, the minimally detectable copy number of RAA was 104. In addition, RAA was nega- tive for the genomic DNA of E. granulosus G1 genotype, T. saginata, T. asiatica, T. multiceps, D. caninum, T. canis, T. trichiura, G. lamblia, F. hepatica, P. westermani, F. gigantica and C. sinensis. The established RAA was positive for detection of the tissue specimens of infected animals, and simulated and field dog stool samples.

CONCLUSIONS

A rapid, sensitive and specific RAA is established, which shows promising values in identification of E. multilocularis and gene diagnosis of alveolar echinococcosis.

From the Soft to the Hard: Changes in Microchemistry During Cell Wall Maturation of Walnut Shells

The walnut shell is a hard and protective layer that provides an essential barrier between the seed and its environment. The shell is based on only one unit cell type: the polylobate sclerenchyma cell. For a better understanding of the interlocked walnut shell tissue, we investigate the structural and compositional changes during the development of the shell from the soft to the hard state. Structural changes at the macro level are explored by X-ray tomography and on the cell and cell wall level various microscopic techniques are applied. Walnut shell development takes place beneath the outer green husk, which protects and delivers components during the development of the walnut. The cells toward this outer green husk have the thickest and most lignified cell walls. With maturation secondary cell wall thickening takes place and the amount of all cell wall components (cellulose, hemicelluloses and especially lignin) is increased as revealed by FTIR microscopy. Focusing on the cell wall level, Raman imaging showed that lignin is deposited first into the pectin network between the cells and cell corners, at the very beginning of secondary cell wall formation. Furthermore, Raman imaging of fluorescence visualized numerous pits as a network of channels, connecting all the interlocked polylobate walnut shells. In the final mature stage, fluorescence increased throughout the cell wall and a fluorescent layer was detected toward the lumen in the inner part. This accumulation of aromatic components is reminiscent of heartwood formation of trees and is suggested to improve protection properties of the mature walnut shell. Understanding the walnut shell and its development will inspire biomimetic material design and packaging concepts, but is also important for waste valorization, considering that walnuts are the most widespread tree nuts in the world.

Decreased expression of long non-coding RNA LINC00261 is a prognostic marker for patients with non-small cell lung cancer: a preliminary study

OBJECTIVE

The previous study found that long non-coding RNA LINC00261 (LINC00261) was significantly down-regulated in non-small cell lung cancer (NSCLC). However, the function of LINC00261 in the progression of NSCLC has not been reported. The present work aimed to explore the prognostic value of LINC00261 in patients with NSCLC.

PATIENTS AND METHODS

The expression of LINC00261 was determined in NSCLC tissues and matched normal lung tissues by quantitative Real-time PCR (qRT-PCR). Furthermore, we evaluated the relationship of LINC00261 and clinicopathological features with survival of patients with NSCLC. Finally, univariate and multivariate Cox regression analyses were used to explore whether LINC00261 was an independent predictor of survival.

RESULTS

We found that the LINC00261 expression level in NSCLC tissues was suppressed compared with that in adjacent normal lung tissues (p < 0.01). Low expression of LINC00261 was found to significantly correlate with TNM stage (p = 0.005), lymph node status (p = 0.020), and distant metastasis (p = 0.004). Then, Kaplan-Meier analysis demonstrated that low LINC00261 expression level was associated with poorer overall survival (p = 0.0013). Furthermore, multivariate analysis showed that low expression of LINC00261 was an independent adverse prognostic factor of NSCLC (p = 0.004).

CONCLUSIONS

We firstly provided evidence that LINC00261 expression was associated with poor prognosis of NSCLC patients and may serve as an independent prognostic indicator.

Expression of Cx43 and Cx45 in Cardiomyocytes of an Overworked Rat Model

Abstract

Objective To study the effect of overwork stress response on the expression of connexin 43（Cx43） and connexin 45（Cx45） in cardiomyocytes and on cardiac function. Methods The experimental animals were divided into control group, overworked 1-month group and overworked 2-month group. A overworked rat model was established by forcing swimming of overworked group. The expressions of Cx43 and Cx45 in myocardial tissues of experimental animals were detected by Western blotting, while the corresponding myocardial tissues were stained with hematoxylin-eosin （HE） staining and Masson's staining, then histologically observed. Results Western blotting results showed that, compared with the control group, Cx43 expression in myocardial tissues of overworked rats decreased while Cx45 expression increased. HE staining and Masson's staining results showed that hypertrophy, rupture and interstitial fiber tissue hyperplasia were observed in myocardial fibers of overworked rats. Conclusion Overwork stress response may affect cardiac function as an independent factor and may even cause heart failure or arrhythmias and lead to death.

The Concept, Status Quo and Forensic Pathology of Karoshi

Abstract

"Karoshi" originates from Japan's economic take-off period in the 1960s and 1970s. It is generally believed that overwork lead to the accumulation of fatigue, which triggers the outbreak of potential diseases, and results in sudden death. Karoshi causes great harm to both the community and families because it occurs primarily in 30 to 60 year old young adults. Japan put Karoshi into the category of industrial injury for the first time in 2001 and started to undertake a series of studies in the sociological and pathological fields. However, there is a tremendous gap in the forensic pathological diagnosis domain. In China, research on Karoshi started from the 1990s and is closely related to the reform and opening up policy as well as economic development. According to the incomplete statistics, 600 thousand people die from overwork each year in China, the highest in the world. Karoshi has become one of the most serious social problems in China at the present stage, thus a systematic study in the sociology and forensic pathology fields is urgently required. This paper summarizes the past and present status of Karoshi, and puts forward the problems that need attention during the judicial expertise of Karoshi from forensic pathology perspective.

The Puzzle of the Walnut Shell: A Novel Cell Type with Interlocked Packing

The outer protective shells of nuts can have remarkable toughness and strength, which are typically achieved by a layered arrangement of sclerenchyma cells and fibers with a polygonal form. Here, the tissue structure of walnut shells is analyzed in depth, revealing that the shells consist of a single, never reported cell type: the polylobate sclereid cells. These irregularly lobed cells with concave and convex parts are on average interlocked with 14 neighboring cells. The result is an intricate arrangement that cannot be disassembled when conceived as a 3D puzzle. Mechanical testing reveals a significantly higher ultimate tensile strength of the interlocked walnut cell tissue compared to the sclerenchyma tissue of a pine seed coat lacking the lobed cell structure. The higher strength value of the walnut shell is explained by the observation that the crack cannot simply detach intact cells but has to cut through the lobes due to the interlocking. Understanding the identified nutshell structure and its development will inspire biomimetic material design and packaging concepts. Furthermore, these unique unit cells might be of special interest for utilizing nutshells in terms of food waste valorization, considering that walnuts are the most widespread tree nuts in the world.

Reversible Self-Assembly of Nanoprobes in Live Cells for Dynamic Intracellular pH Imaging

Self-assembly is a powerful tool to organize the elementary molecular units into functional nanostructures, which provide reversible stimulus-responsive systems for a variety of purposes. However, the ability to modulate the reversible self-assembly in live systems remains a great challenge owing to the chemical complexity of intracellular environments, which often damage synthetic assembled superstructures. Herein, we describe a robust reversible self-assembly system that is composed of a hydrophobic gold nanoparticle (AuNP) core and a shell of pH-responsive dye-incorporated block copolymers. The reversible assembly-disassembly processes were precisely controlled through mediating the molecular interactions between the copolymers and AuNPs. More importantly, the major endogenous biospecies such as proteins will not impair the reversible self-assembly, which was supported by free-energy calculations. The reversible pH-responsive nanostructures were employed as "smart" probes for visualizing the subtle dynamic pH changes among different intracellular compartments, facilitating the study of pH influence on biological processes.