Toughening mechanisms of the elytra of the diabolical ironclad beetle.

Joining dissimilar materials such as plastics and metals in engineered structures remains a challenge1. Mechanical fastening, conventional welding and adhesive bonding are examples of techniques currently used for this purpose, but each of these methods presents its own set of problems2 such as formation of stress concentrators or degradation under environmental exposure, reducing strength and causing premature failure. In the biological tissues of numerous animal and plant species, efficient strategies have evolved to synthesize, construct and integrate composites that have exceptional mechanical properties3. One impressive example is found in the exoskeletal forewings (elytra) of the diabolical ironclad beetle, Phloeodes diabolicus. Lacking the ability to fly away from predators, this desert insect has extremely impact-resistant and crush-resistant elytra, produced by complex and graded interfaces. Here, using advanced microscopy, spectroscopy and in situ mechanical testing, we identify multiscale architectural designs within the exoskeleton of this beetle, and examine the resulting mechanical response and toughening mechanisms. We highlight a series of interdigitated sutures, the ellipsoidal geometry and laminated microstructure of which provide mechanical interlocking and toughening at critical strains, while avoiding catastrophic failure. These observations could be applied in developing tough, impact- and crush-resistant materials for joining dissimilar materials. We demonstrate this by creating interlocking sutures from biomimetic composites that show a considerable increase in toughness compared with a frequently used engineering joint.

Bloodstream infection caused by Wickerhamiella pararugosa in a patient with intestinal obstruction: A case report.

The fungus Wickerhamiella pararugosa (Candida pararugosa) has been detected in various human organs but has rarely caused bloodstream infections. This report presents a case of central venous catheter-related bloodstream infection (CRBSI) of W. pararugosa in an adult. A female patient in her 80s was admitted to our facility for intestinal obstruction caused by colorectal cancer. The patient's ability to consume food was hindered, necessitating the insertion of a central venous catheter (CVC) into the internal jugular vein. On day 3 after admission, the patient developed a fever, prompting blood and CVC tip cultures to be performed. On day 5, yeast-like fungi were discovered in the blood cultures, and fosfluconazole (fluconazole [FLCZ] pro-drug) treatment was initiated. On day 8, yeast-like fungi were identified in both the blood and CVC tip cultures, leading to a diagnosis of CRBSI. The fungus was identified as W. pararugosa through biochemical and genetic characterization. This finding justified the use of micafungin (MCFG) for combination therapy. On day 17, the minimum inhibitory concentrations (MIC) for FLCZ and MCFG were 4-8 and 0.06 µg/mL, respectively. Accordingly, the treatment was changed to monotherapy with MCFG. After a 21-day treatment regimen, the patient was discharged on day 31. We present a case of CRBSI caused by W. pararugosa in an adult with intestinal obstruction. The notable increase in the MIC of FLCZ necessitated monotherapy with MCFG, which resulted in successful recovery of the patient.

Nanoarchitected Tough Biological Composites from Assembled Chitinous Scaffolds.

Over hundreds of millions of years, organisms have derived specific sets of traits in response to common selection pressures that serve as guideposts for optimal biological designs. A prime example is the evolution of toughened structures in disparate lineages within plants, invertebrates, and vertebrates. Extremely tough structures can function much like armor, battering rams, or reinforcements that enhance the ability of organisms to win competitions, find mates, acquire food, escape predation, and withstand high winds or turbulent flow. From an engineering perspective, biological solutions are intriguing because they must work in a multifunctional context. An organism rarely can be optimally designed for only one function or one environmental condition. Some of these natural systems have developed well-orchestrated strategies, exemplified in the biological tissues of numerous animal and plant species, to synthesize and construct materials from a limited selection of available starting materials. The resulting structures display multiscale architectures with incredible fidelity and often exhibit properties that are similar, and frequently superior, to mechanical properties exhibited by many engineered materials. These biological systems have accomplished this feat through the demonstrated ability to tune size, morphology, crystallinity, phase, and orientation of minerals under benign processing conditions (i.e., near-neutral pH, room temperature, etc.) by establishing controlled synthesis and hierarchical 3D assembly of nano- to microscaled building blocks. These systems utilize organic-inorganic interactions and carefully controlled microenvironments that enable kinetic control during the synthesis of inorganic structures. This controlled synthesis and assembly requires orchestration of mineral transport and nucleation. The underlying organic framework, often consisting of polysaccharides and polypeptides, in these composites is critical in the spatial and temporal regulation of these processes. In fact, the organic framework is used not only to provide transport networks for mineral precursors to nucleation sites but also to precisely guide the formation and phase development of minerals and significantly improve the mechanical performance of otherwise brittle materials.Over the past 15 years, we have focused on a few of these extreme performing organisms, (Wang , Adv. Funct. Mater. 2013, 23, 2908; Weaver , Science 2012, 336, 1275; Huang , Nat. Mater. 2020, 19, 1236; Rivera , Nature 2020, 586, 543) investigating not only their ultrastructural features and mechanical properties but in some cases, how these assembled structures are mineralized. In specific instances, comparative analyses of multiscale structures have pinpointed which design principles have arisen convergently; when more than one evolutionary path arrives at the same solution, we have a good indication that it is the best solution. This is required for survival under extreme conditions. Indeed, we have found that there are specific architectural features that provide an advantage toward survival by enabling the ability to feed effectively or to survive against predatory attacks. In this Account, we describe 3 specific design features, nanorods, helicoids, and nanoparticles, as well as the interfaces in fiber-reinforced biological composites. We not only highlight their roles in the specific organisms but also describe how controlled syntheses and hierarchical assembly using organic (i.e., often chitinous) scaffolds lead to these integrated macroscale structures. Beyond this, we provide insight into multifunctionality: how nature leverages these existing structures to potentially add an additional dimension toward their utility and describe their translation to biomimetic materials used for engineering applications.

BCS1L mutations produce Fanconi syndrome with developmental disability.

Fanconi syndrome is a functional disorder of the proximal tubule, characterized by pan-aminoaciduria, glucosuria, hypophosphatemia, and metabolic acidosis. With the advancements in gene analysis technologies, several causative genes are identified for Fanconi syndrome. Several mitochondrial diseases cause Fanconi syndrome and various systemic symptoms; however, it is rare that the main clinical symptoms in such disorders are Fanconi syndrome without systematic active diseases like encephalomyopathy or cardiomyopathy. In this study, we analyzed two families exhibiting Fanconi syndrome, developmental disability and mildly elevated liver enzyme levels. Whole-exome sequencing (WES) detected compound heterozygous known and novel BCS1L mutations, which affect the assembly of mitochondrial respiratory chain complex III, in both cases. The pathogenicity of these mutations has been established in several mitochondria-related functional analyses in this study. Mitochondrial diseases with isolated renal symptoms are uncommon; however, this study indicates that mitochondrial respiratory chain complex III deficiency due to BCS1L mutations cause Fanconi syndrome with developmental disability as the primary indications.

Adsorption of Biomineralization Protein Mms6 on Magnetite (Fe3O4) Nanoparticles.

Biomineralization is an elaborate process that controls the deposition of inorganic materials in living organisms with the aid of associated proteins. Magnetotactic bacteria mineralize magnetite (Fe3O4) nanoparticles with finely tuned morphologies in their cells. Mms6, a magnetosome membrane specific (Mms) protein isolated from the surfaces of bacterial magnetite nanoparticles, plays an important role in regulating the magnetite crystal morphology. Although the binding ability of Mms6 to magnetite nanoparticles has been speculated, the interactions between Mms6 and magnetite crystals have not been elucidated thus far. Here, we show a direct adsorption ability of Mms6 on magnetite nanoparticles in vitro. An adsorption isotherm indicates that Mms6 has a high adsorption affinity (Kd = 9.52 µM) to magnetite nanoparticles. In addition, Mms6 also demonstrated adsorption on other inorganic nanoparticles such as titanium oxide, zinc oxide, and hydroxyapatite. Therefore, Mms6 can potentially be utilized for the bioconjugation of functional proteins to inorganic material surfaces to modulate inorganic nanoparticles for biomedical and medicinal applications.

Cascaded pattern formation in hydrogel medium using the polymerisation approach.

Reaction-diffusion systems are one of the models of the formation process with various patterns found in nature. Inspired by natural pattern formation, several methods for designing artificial chemical reaction-diffusion systems have been proposed. DNA is a suitable building block to build such artificial systems owing to its programmability. Previously, we reported a line pattern formed due to the reaction and diffusion of synthetic DNA; however, the width of the line was too wide to be used for further applications such as parallel and multi-stage pattern formations. Here, we propose a novel method to programme a reaction-diffusion system in a hydrogel medium to realise a sharp line capable of forming superimposed and cascaded patterns. The mechanism of this system utilises a two-segment polymerisation of DNA caused by hybridisation. To superimpose the system, we designed orthogonal DNA sequences that formed two lines in different locations on the hydrogel. Additionally, we designed a reaction to release DNA and form a cascade pattern, in which the third line appears between the two lines. To explain the mechanism of our system, we modelled the system as partial differential equations, whose simulation results agreed well with the experimental data. Our method to fabricate cascaded patterns may inspire combinations of DNA-based technologies and expand the applications of artificial reaction-diffusion systems.

A Prospective Multicenter Observational Study of Venous Thromboembolism after Gastric Cancer Surgery (SHISA-1601).

INTRODUCTION: This study aimed to clarify the frequency and risk factors of intercurrent venous thromboembolism (VTE) in patients undergoing major curative gastric cancer surgery. METHODS: This prospective, multicenter, observational study included patients with gastric cancer who underwent radical gastrectomy at 5 hospitals between June 2016 and May 2018. Patients who were preoperatively administered anticoagulants were excluded. RESULTS: A total of 126 patients were eligible to participate. VTE occurred within 9 days postoperatively in 5 cases (4.0%; 2 symptomatic and 3 asymptomatic). Postoperative day (POD) 1 plasma D-dimer and soluble fibrin (SF) levels were significantly higher in the VTE group than in the non-VTE group. Receiver-operating characteristic curve (ROC) analysis indicated a statistically significant ability of POD 1 D-dimer and SF levels to predict postoperative VTE development after gastrectomy; this finding was reflected by an area under the curve (AUC) of 0.97 (95% CI 0.92-1.0) and 0.87 (95% CI 0.74-1.0), respectively. Cutoff values of D-dimer (24.6 µg/mL) and SF (64.1 µg/mL) were determined. Intraoperative blood transfusion (odds ratio [OR] 7.86), POD 1 D-dimer ≥24.6 µg/mL (OR 17.35), and POD 1 SF ≥64.1 µg/mL (OR 19.5) were independent predictive factors for postoperative VTE (p < 0.05). CONCLUSION: VTE occurred in 4.0% patients (1.6% symptomatic and 2.4% asymptomatic) after gastric cancer surgery; however, with an early diagnosis and anticoagulant therapy, no patients experienced progression. Careful observation of patients with a high risk for VTE, including intraoperative blood transfusion and high POD 1 D-dimer or SF levels, would contribute to the early detection of VTE.

A Novel Technique to Predict Liver Damage After Laparoscopic Gastrectomy From the Stomach Volume Overlapping the Liver by Preoperative Computed Tomography.

BACKGROUND: During laparoscopic gastrectomy (LG), it is necessary to manipulate the lateral segment of the liver to secure the surgical field. Liver retraction during surgery often causes liver dysfunction after LG. However, no previous studies have used preoperative image evaluations to predict postoperative liver damage associated with surgical retraction. We aimed to predict postoperative liver damage after LG. METHODS: In all, 117 consecutive patients with gastric cancer who underwent LG were included in this study. Using preoperative computed tomography (CT), the volume of the stomach overlapping the liver was integrated and calculated as the liver projecting stomach volume (LPSV). The liver projection ratio (LPR) was calculated by dividing the LPSV by the volume of the whole stomach. The relationships among liver damage, the LPSV and LPR were evaluated. RESULTS: A total of 112 patients were divided into two groups as follows: 33 patients in the liver dysfunction group (D group) and 79 patients in the non-dysfunction group (N group). The LPSV was significantly larger in the D group than in the N group (median 77.1 vs 50.1 cm3; p = 0.0061). Similarly, LPR values in the D group were significantly higher than those in the N group (median 33.6 vs 26.2%; p = 0.003). Receiver operating characteristic curve analysis indicated a statistically significant ability of the LPSV and LPR to predict postoperative liver damage (area under the curve; 0.705 and 0.735, respectively). Furthermore, multivariate logistic regression analysis revealed that the increase in the LPR was an independent predictor of postoperative liver damage (odds ratio: 1.042; 95% confidence interval: 1.009-1.078; p = 0.019). CONCLUSIONS: We have developed a novel technique for predicting postoperative liver damage associated with surgical liver retraction following LG. This method confirms the degree of the LPSV and LPR of the stomach via preoperative CT.

DNA cytoskeleton for stabilizing artificial cells.

Cell-sized liposomes and droplets coated with lipid layers have been used as platforms for understanding live cells, constructing artificial cells, and implementing functional biomedical tools such as biosensing platforms and drug delivery systems. However, these systems are very fragile, which results from the absence of cytoskeletons in these systems. Here, we construct an artificial cytoskeleton using DNA nanostructures. The designed DNA oligomers form a Y-shaped nanostructure and connect to each other with their complementary sticky ends to form networks. To undercoat lipid membranes with this DNA network, we used cationic lipids that attract negatively charged DNA. By encapsulating the DNA into the droplets, we successfully created a DNA shell underneath the membrane. The DNA shells increased interfacial tension, elastic modulus, and shear modulus of the droplet surface, consequently stabilizing the lipid droplets. Such drastic changes in stability were detected only when the DNA shell was in the gel phase. Furthermore, we demonstrate that liposomes with the DNA gel shell are substantially tolerant against outer osmotic shock. These results clearly show the DNA gel shell is a stabilizer of the lipid membrane akin to the cytoskeleton in live cells.

Large Deformation of a DNA-Origami Nanoarm Induced by the Cumulative Actuation of Tension-Adjustable Modules.

Making use of the programmability and structural flexibility of the DNA molecule, a DNA-origami nanoarm capable of undergoing large deformation is constructed. This DNA-origami nanoarm comprised serially repeated tension-adjustable modules, the cumulative actuation of which resulted in a large deformation of the arm structure, which transformed from a linear shape into an arched shape. Combining atomic force microscopy and theoretical analyses based on the mechanics of materials, we demonstrate that the degree of deformation can be systematically controlled by merely replacing a set of strands that is required for the actuation of the module. Moreover, by employing a G-quadruplex-forming sequence for the actuation, we could achieve reversible ion-induced contraction and relaxation of the nanoarm. The adjustability and scalability of this design could enable the production of DNA nanodevices that exhibit large deformation in response to external stimuli.

DNA Origami "Quick" Refolding Inside of a Micron-Sized Compartment.

Investigations into the refolding of DNA origami leads to the creation of reconstructable nanostructures and deepens our understanding of the sustainability of life. Here, we report the refolding of the DNA origami structure inside a micron-sized compartment. In our experiments, conventional DNA origami and truss-type DNA origami were annealed and purified to remove the excess staples in a test tube. The DNA origami was then encapsulated inside of a micron-sized compartment of water-in-oil droplets, composed of neutral surfactants. The re-annealing process was then performed to initiate refolding in the compartment. The resulting 100-nm-sized DNA nanostructures were observed using atomic force microscopy (AFM), and the qualities of their structures were evaluated based on their shape. We found that the refolding of the DNA origami structure was favored inside the droplets compared with refolding in bulk solution. The refolded structures were able to fold even under "quick" one-minute annealing conditions. In addition, the smaller droplets (average diameter: 1.2 µm) appeared to be more advantageous for the refolding of the origamis than larger droplets. These results are expected to contribute to understanding the principles of life phenomena based on multimolecular polymer self-assembly in a micron-sized compartment, and for the production and maintenance of artificially designed molecules.

[Study of Eight Cases of Retroperitoneal Liposarcoma].

Retroperitoneal liposarcoma is a relatively rare disease, with a high recurrence rate and poor prognosis. We encountered 8 patients with retroperitoneal liposarcoma who underwent surgery in Shiga University of Medical Science Hospital. We often encounter elderly male patients without symptoms. Of the 8 patients, 6 received extensive resection that included the surrounding organs or tissues; however, 3 patients demonstrated positive surgical margins, which resulted in liposarcoma recurrence. Despite the additional resection in the 3 recurrent cases, all the patients had a tumor relapse. One patient with an unresectable tumor received chemotherapy. The other patients received surgical treatment 3 times. One patient developed an unresectable relapse after receiving chemotherapy. Another patient attained long-term survival by adjuvant chemoradiotherapy combined with 3 surgeries. Aggressive surgical resection to achieve a negative surgical margin and careful postoperative follow-up seem important for the treatment of retroperitoneal liposarcoma. This study suggests that postoperative adjuvant therapy may contribute to the improvement of prognosis. Further findings must be accumulated to clarify the significance of postoperative adjuvant therapies in the future.

In vivo antitumor function of tumor antigen-specific CTLs generated in the presence of OX40 co-stimulation in vitro.

Adoptive cell transfer (ACT) is an emerging and promising cancer immunotherapy that has been improved through various approaches. Here, we described the distinctive characteristics and functions of tumor Ag-specific effector CD8+ T-cells, co-cultured with a tumor-specific peptide and a stimulatory anti-OX40 antibody, before being used for ACT therapy in tumor-bearing mouse recipients. Splenic T-cells were obtained from wild-type FVB/N mice that had been injected with a HER2/neu (neu)-expressing tumor and a neu-vaccine. The cells were then incubated for 7 days in vitro with a major histocompatibility complex (MHC) class I peptide derived from neu, in the presence or absence of an agonistic anti-OX40 monoclonal antibody, before CD8+ T cells were isolated for use in ACT therapy. The proliferative ability of OX40-driven tumor Ag-specific effector CD8+ T-cells in vitro was less than that of non-OX40-driven tumor Ag-specific effector CD8+ T-cells, but they expressed significantly more early T-cell differentiation markers, such as CD27, CD62L and CCR7, and significantly higher levels of Bcl-2, an anti-apoptotic protein. These OX40-driven tumor Ag-specific effector CD8+ T-cells, when transferred into tumor-bearing recipients, demonstrated potent proliferation capability and successfully eradicated the established tumor. In addition, these cells exhibited long-term antitumor function, and appeared to be established as memory T-cells. Our findings suggest a possible in vitro approach for improving the efficacy of ACT, which is simple, requires only a small amount of modulator, and can potentially avoid several toxicities associated with co-stimulation in vivo.

Construction of T-Motif-Based DNA Nanostructures through Enzymatic Reactions.

The most common way to fabricate DNA nanostructures is to mix individually synthesized DNA oligomers in one pot. However, if DNA nanostructures could be produced through enzymatic reactions, they could be applied in various environments, including in vivo. Herein, an enzymatic method developed to construct a DNA nanostructure from a simple motif called a T-motif is reported. A long, repeated structure was replicated from a circular template by rolling circle amplification and then cleaved into T-motif segments by restriction enzymes. These motifs have been successfully assembled into a ladder-like nanostructure without purification or controlled annealing. This approach is widely applicable to constructing a variety of DNA nanostructures through enzymatic reactions.

5-fluorouracil combined with cisplatin and mitomycin C as an optimized regimen for hyperthermic intraperitoneal chemotherapy in gastric cancer.

BACKGROUND AND OBJECTIVES: Optimized drug regimens for hyperthermic intraperitoneal chemotherapy (HIPEC) have not been standardized completely in patients with advanced gastric cancer (GC). We evaluated an optimized anti-tumor protocol comprising 5-fluorouracil (5-FU) combined with cisplatin (CDDP) and mitomycin C (MMC) in vitro for clinical use of HIPEC. METHODS: The sensitivities of 5-FU, CDDP, or MMC, alone or in combination, using different drug concentrations, exposure times, and hyperthermic conditions (42°C) were determined in vitro by the CD-DST method using 3 different differentiated GC cell lines. RESULTS: The tumor cell growth-inhibitory effect of 5-FU was concentration-dependent for all cell lines. In addition, 5-FU showed a hyperthermic sensitization effect at all drug concentrations for all cell lines. The appropriate concentration of each drug was 5-FU, 200 µg/mL; CDDP, 10 µg/mL; MMC, 2 µg/mL. Under hyperthermic conditions, most growth-inhibitory effects for each drug at 30 min was equivalent to 60 min of exposure; use of three drugs combined significantly inhibited growth compared with any of the drugs alone. CONCLUSION: An appropriate in vitro intraperitoneal chemotherapy regimen for GC was combined use of 5-FU, CDDP, and MMC at 42°C for 30 min.

Classification of remnant stomach shape after distal gastrectomy with Billroth-I reconstruction and a comparison of the postoperative outcomes.

PURPOSE: To classify the shape of the remnant stomach after Billroth-I (B-I) reconstruction and evaluate the relationship between the shape of the remnant stomach and the postoperative clinical outcomes. METHODS: One hundred and ninety-five consecutive patients with gastric cancer underwent distal gastrectomy with B-I reconstruction between May 2006 and October 2014. We retrospectively reviewed their medical records and radiological findings. Finally, the shapes of the remnant stomach of 150 patients were classified as either straight type (type A) or stagnant type (type B). The clinical outcomes were compared with respect to the types of remnant stomach. RESULTS: The incidence of anastomotic leakage was significantly higher in the type A group than in the type B group (9.4 vs. 1.5%, p = 0.044). The body weight change ratio after surgery was significantly lower in the type B group than in the type A group [p = 0.0068, two-way repeated measures analysis of variance (ANOVA)], while the serum albumin levels showed marginally significant improvement in the type B group compared with the type A group (p = 0.0542, two-way repeated measures ANOVA). CONCLUSION: The shape of the remnant stomach after distal gastrectomy with B-I reconstruction might influence the degree of anastomotic leakage and long-term nutritional status.

[A Case of Gastric Cancer Underwent Two-Stage Gastrectomy after Chemotherapy-Induced Perforation].

A 70's man presenting with a chief complaint of stomachache was found to have advanced gastric cancer with a deep ulcer and some lymph-node metastases. We decided performing a curative operation after 2 courses of S-1 plus cisplatin. On the first course day 13 of chemotherapy, he complained of severe epigastralgia, and we diagnosed as generalized peritonitis due to perforation of gastric cancer. We performed an urgent laparoscopic operation, which made perforation simple closure and omentopexy. Curative distal gastrectomy with D2 lymph node dissection was successfully performed on postoperative day 16.

Prognostic impact of CD44-positive cancer stem-like cells at the invasive front of gastric cancer.

BACKGROUND: The invasive tumour front may provide prognostic information. We examined the relationship between the presence of cancer stem cells (CSCs) at the invasive tumour front and prognosis in gastric cancer (GC). METHODS: CD44 is a CSC marker; accordingly, CD44 standard (CD44s), CD44 variant-6 (CD44v6), and CD44 variant-9 (CD44v9) expression were examined in 123 resected primary GCs and the clinical significance of CSCs at the invasive tumour front was analysed. RESULTS: Thirteen (10.6%), 79 (64.2%), and 47 (38.2%) GCs were CD44s-, CD44v6-, and CD44v9-positive, respectively. Patients with CD44-positive expression at the invasive tumour front had significantly poorer disease-specific survival than those with negative expression (CD44s: P<0.00001, CD44v6: P=0.013, CD44v9: P=0.0002). CD44s expression at the invasive tumour front was an independent prognostic factor in resectable GC patients (hazard ratio=3.13; 95% confidence interval, 1.09-9.01; P=0.035) and was significantly associated with peritoneal (P<0.001), lymphatic (P<0.001), and haematogenous recurrences (P=0.008). In addition, the number of CD44 isoforms expressed in cancer cells at the invasive tumour front was associated with patient prognosis. No conventional clinicopathological factors were independently associated with CD44 expression at the invasive tumour front. CONCLUSIONS: CD44-positive cancer stem-like cells at the invasive tumour front indicate poor survival and can be a unique biological prognostic factor for GC.

Revolving Vernier Mechanism Controls Size of Linear Homomultimer.

A new kind of the Vernier mechanism that is able to control the size of linear assembly of DNA origami nanostructures is proposed. The mechanism is realized by mechanical design of DNA origami, which consists of a hollow cylinder and a rotatable shaft in it connected through the same scaffold. This nanostructure stacks with each other by the shape complementarity at its top and bottom surfaces of the cylinder, while the number of stacking is limited by twisting angle of the shaft. Experiments have shown that the size distribution of multimeric assembly of the origami depends on the twisting angle of the shaft; the average lengths of the multimer are decamer, hexamer, and tetramer for 0°, 10°, and 20° twist, respectively. In summary, it is possible to affect the number of polymerization by adjusting the precise shape and movability of a molecular structure.