Photoinduced Decarboxylative Difluoroalkylation and Perfluoroalkylation of α-Fluoroacrylic Acids.

Herein, a novel and practical methodology for the photoinduced decarboxylative difluoroalkylation and perfluoroalkylation of α-fluoroacrylic acids is reported. A wide range of α-fluoroacrylic acids can be used as applicable feedstocks, allowing for rapid access to structurally important difluoroalkylated and polyfluoroalkylated monofluoroalkenes with high Z-stereoselectivity under mild conditions. The protocol demonstrates excellent functional group compatibility and provides a platform for modifying complex biologically active molecules.

Differences in anterior chamber depth in keratoconus patients with binocular very asymmetry ectasia.

BACKGROUND: To evaluate the difference in anterior chamber depth (ACD) between two eyes among keratoconus patients with binocular very asymmetric ectasia (VAE) and to explore the influencing factors. METHODS: The corneal curvature and ACD in both eyes of patients with VAE were measured by Sirius (version 3.2, CSO, Italy) at the following points: corneal vertex, maximum curvature (apex), and the 1.5 mm, 2.5 mm, and 3.5 mm superior-, inferior-, nasal-, temporal-paracentral from center. The mean pupil power (MPP) and corneal morphology parameters were also measured. Correlations between ACD and curvature and morphology parameters were analyzed by linear regression. RESULTS: 172 eyes of 86 patients (9 to 45 years) were classified into the VAE-N (n = 86) group and the VAE-E group (n = 86) based on the corneal morphology. The central (3.32 ± 0.27 mm versus 3.43 ± 0.29 mm, P < 0.001) and paracentral ACDs increased significantly in the VAE-E group, and the corneal morphology parameters were also significantly higher. The central ACD was significantly correlated with the MPP (r = 0.465), KVf/b (Keratoconus Vertex front/back) (r = 0.306, r = 0.327), and BCVf/b (Baiocchi Calossi Versaci front/back) (r = 0.356, r = 0.416). Linear regression showed good relationships between △ACD and △MPP (R2 = 0.429) and △KVf/b (R2 = 0.504, R2 = 0.536). CONCLUSIONS: The ACD was larger in the VAE-E group. The difference in ACD between the VAE-E and VAE-N groups was significantly correlated with corneal curvature and the extent of corneal elevation, indicating the influences of both the corneal magnification effect and corneal ectasia on ACD.

Systemic lupus erythematosus and risk of sexual dysfunction: A systematic review and Meta-Analysis.

OBJECTIVE: To systematically review and summarize the available literature regarding the association between systemic lupus erythematosus (SLE) and sexual dysfunction (SD) in both sexes. METHODS: We retrieved relevant studies from the following databases: PubMed, Embase,Cochrane Library, and Web of Science. Two reviewers independently reviewed the studies in our sample, assessed their validity, and extracted relevant data. Sensitivity and subgroup analyses were performed to distinguish sources of heterogeneity. RESULTS: Our search resulted in a sample of eight eligible studies, which involved 758 patients in the SLE group and 1724 individuals in the control group. The pooled RR for the increased risk for SD compared to those in the control group was 1.80 (95%CI 1.12-2.87). Subgroup analysis by sex revealed that males (pooled RR = 2.98, 95%CI 2.41-3.68) had a higher risk of SD compared to females (pooled RR = 1.56, 95%CI 0.99-2.48). Females with SLE had significantly lower values in FSFI compared to the healthy individuals (WMD=-0.224, 95%CI -0.441 to -0.078). Age of participants and the quality of studies might influence the results. CONCLUSIONS: Our meta-analysis suggests that SLE is significantly associated with an increased risk of sexual dysfunction. It is of great urgency to implement for active interventions that aimed to treat or prevent SD among SLE patients.

[Clinical effect of white noise combined with glucose in reducing the pain of retinopathy screening in preterm infants].

OBJECTIVE: To study the clinical effect of white noise combined with glucose in reducing the procedural pain of retinopathy screening in preterm infants. METHODS: A total of 396 preterm infants with a gestational age of 28-34 weeks and a birth weight of ≤2 000 g were randomly divided into 4 groups according to the intervention method for reducing pain in retinopathy screening: control group with 100 infants (no white noise or glucose intervention), white noise group with 96 infants, glucose group with 98 infants and white noise + glucose group with 102 infants. The Premature Infant Pain Profile (PIPP) was used to determine pain score during retinopathy screening, and the four groups were compared in terms of PIPP score before and after retinopathy screening. RESULTS: There were no significant differences in PIPP score, heart rate and blood oxygen saturation between the four groups at 3 minutes before screening (P>0.05). At 1 and 5 minutes after screening, the white noise, glucose and white noise + glucose groups had significantly lower heart rate and PIPP score but significantly higher blood oxygen saturation than the control group (P<0.05).The white noise + glucose group had significantly lower heart rate and PIPP score but significantly higher blood oxygen saturation than the white noise and glucose groups (P<0.05). CONCLUSIONS: White noise combined with glucose can reduce the procedural pain of retionopathy screening and keep vital signs stable in preterm infants.

An Exfoliated 2D Egyptian Blue Nanosheet for Highly Selective Enrichment of Multi-phosphorylated Peptides in Mass Spectrometric Analysis.

Phosphopeptide enrichment is essential for the phosphoprotein profiling, due to the low abundance in complex biological samples. Moreover, selective binding of multi-phosphopeptides over mono-phosphopeptides is rarely established, but strongly needed in real sample analysis, especially for the investigation of cell behaviors with the multisite phosphorylation cascades. Here two-dimensional (2D) nanosheets were synthesized of Egyptian blue (CaCuSi4 O10 ), the well-known ancient pigment, and its analogues (SrCuSi4 O10 and BaCuSi4 O10 ), which were employed in the enrichment of phosphopeptides for the first time. Surprisingly, the 2D CaCuSi4 O10 nanosheet was highly selective towards multi-phosphopeptides without enriching the mono-phosphorylated peptides in a wide range of acidic conditions or buffer compositions. Meanwhile, the SrCuSi4 O10 and BaCuSi4 O10 nanosheet analogues do not exhibit this unique selectivity. Moreover, the ultrathin and well-defined 2D morphology, with abundant CaII , of Egyptian blue nanosheet was applied in cortical samples of forebrain specific PDK1 conditional knockout mice and their age-matched littermate controls, that are associated with Alzheimer's disease. The as-prepared 2D CaCuSi4 O10 nanosheet not only showed specific selectivity, but also exhibited high sensitivity (detection limit of 4×10-7 m).

[Study on breeding and pollination characteristics of Gleditsia sinensis].

To study the breeding system and pollination characteristics of Gleditsia sinensis, we observed the development of flower development and the processing of pollination, and determined the pollen viability and stigma acceptability by TTC and benzidine-hydrogen peroxide method and detected its breeding system using OCI value, P/O ratio and artificial pollination.The results showed that: ①G. sinensis are racemes, divided into bisexual inflorescences (only a small amount of inactive pollen) and male inflorescences (occasionally a few bisexual flowers), flowers hermaphrodite. ②Male flowers had the strongest pollen activity 4 h after flowering; the stigma receptivity of bisexual was the highest at 1 h after flowering, and pollination was the best in this time. ③The pollen tube had a few elongation when the bisexual flower is half-opened. The number of pollen tube and length significantly increased when blooming. The flower reaches the ovary and even enters the ovule to complete the fertilization. ④When the OCI=4 and P/O=11 684, it means that the breeding system was facultative, outcrossing, and requiring pollinators based on the results of the bagging experiment.There was parthenogenesis. ⑤The characteristics of saponin pollination were wind pollination and insect vector pollination, and pollinators were initially identified as Apis mellifera ligustica. All these results provides a theoretical and technical foundation for the new germplasm of G. sinensis.

[MiR-26b inhibits proliferation, invasion, and migration of glioma by targeting cyclooxygenase-2].

OBJECTIVE: To explore the expressions of miR-26b and cyclooxygenase (COX)-2 in different grades of gliomas and the effect of miR-26b on glioma cell proliferation, invasion and migration.
 Methods: Western blot and Real-time quantitative PCR (qRT-PCR) were used to detect the expression levels of miR-26b and COX-2 in different grades of gliomas. Human glioma cells were transfected with miR-26b mimics. qRT-PCR was employed to detect the mRNA expressions of miR-26b and COX-2 after miR-26b mimics transfection, while dual-luciferase reporter assay was used to investigate the regulatory effect of miR-26b on COX-2. Cell counting kit-8 (CCK8), trans-well invasion assay and scratch assay were used to detect the proliferation, invasion and migration of human U87 glioma cells after miR-26b mimic transfection, respectively. The antitumor effect of miR-26b was verified by evaluating the volume and weight of tumor in nude mice.
 Results: With the increase in tumor grades, the expression of miR-26b was significantly decreased (P<0.05), while COX-2 expression was increased (P<0.001). Dual luciferase assay confirmed that miR-26b could directly regulate the protein expression of COX-2. MiR-26b mimics could significantly reduce the expression of COX-2 (P<0.05) and suppress the proliferation, invasion and migration of glioma cell (P<0.05). The volume and weight of tumor in MiR-26b mimics transfection group were smaller than those in the control group.
 Conclusion: Overexpression of miR-26b may inhibit proliferation, invasion, and migration of glioma by suppressing the expression of COX-2. Therefore, the miR-26b/COX-2 pathway might be a therapeutic target in glioma.

Multifunctional Therapeutic Nanodiamond Hydrogels for Infected-Wound Healing and Cancer Therapy.

Wound infection and tumor recurrence are the two main threats to cancer patients after surgery. Although researchers have developed new treatment systems to address the two significant challenges simultaneously, the potential side effects of the heavy-metal-ion-based treatment systems still severely limit their widespread application in therapy. In addition, the wounds from tumor removal compared with general operative wounds are more complex. The tumor wounds mainly exhibit more hemorrhage, larger trauma area, greater vulnerability to bacterial infection, and residual tumor cells. Therefore, a multifunctional treatment platform is urgently needed to integrate rapid hemostasis, sterilization, wound healing promotion, and antitumor functions. In this work, nanodiamonds (NDs), a material that has been well proven to have excellent biocompatibility, are added into a solution of acrylic-grafted chitosan (CEC) and oxidized hyaluronic acid (OHA) to construct a multifunctional treatment platform (CEC-OHA-NDs). The hydrogels exhibit rapid hemostasis, a wound-healing-promoting effect, excellent self-healing, and injectable abilities. Moreover, CEC-OHA-NDs can effectively eliminate bacteria and inhibit tumor proliferation by the warm photothermal effect of NDs under tissue-penetrable near-infrared laser irradiation (NIR) without cytotoxicity. Consequently, we adopt a simple and convenient strategy to construct a multifunctional treatment platform using carbon-based nanomaterials with excellent biocompatibility to promote the healing of infected wounds and to inhibit tumor cell proliferation simultaneously.

Volatile carbonyl metabolites analysis of nanoparticle exposed lung cells in an organ-on-a-chip system.

The evaluation of nanoparticles (NPs) cytotoxicity is crucial for advancing nanotechnology and assessing environmental pollution. However, existing methods for NPs cytotoxicity evaluation suffer from limited accuracy and inadequate information content. In the study, we developed a novel detection platform that enables the identification of cellular carbonyl metabolites at the organ level. The platform is integrated with a cell co-culture lung organ chip (LOC) and a micropillar concentrator. Notably, our work represents the successful measurement of the amounts of cellular metabolites on LOC system. The volatile carbonyl metabolites (VCMs) generated by cells exposure to various types of NPs with different concentrations were captured and detected by high-resolution mass spectrometry (MS). Compared with conventional cell viability and reactive oxygen species (ROS) analysis, our method discerns the toxicological impact of NPs at low concentrations by analyzed VCM at levels as low as ppb level. The LOC system based metabolic gas detection confirmed that low concentrations of NPs have a toxic effect on the cell model, which was not reflected in the fluorescence detection, and the effect of NP material is more significant than the size effect. Furthermore, this method can distinguish different NPs acting on cell models through cluster analysis of multiple VCMs.

Photoinduced decarboxylative germylation of α-fluoroacrylic acids: access to germylated monofluoroalkenes.

Herein, a novel strategy is presented for the photoinduced decarboxylative and dehydrogenative cross-coupling of a wide range of α-fluoroacrylic acids with hydrogermanes. This methodology provides an efficient and robust approach for producing various germylated monofluoroalkenes with excellent stereoselectivity within a brief photoirradiation period. The feasibility of this reaction has been demonstrated through gram-scale reaction, conversion of germylated monofluoroalkenes, and modification of complex organic molecules.

Exosomal membrane proteins analysis using a silicon nanowire field effect transistor biosensor.

Exosomes are of great significance in clinical diagnosis, due to their high homology with parental generation, which can reflect the pathophysiological status. However, the quantitative and classification detection of exosomes is still faced with the challenges of low sensitivity and complex operation. In this study, we develop an electrical and label-free method to directly detect exosomes with high sensitivity based on a Silicon nanowire field effect transistor biosensor (Si-NW Bio-FET). First, the impact of Debye length on Si-NW Bio-FET detection was investigated through simulation. The simulation results demonstrated that as the Debye length increased, the electrical response to Si-NW produced by charged particle at a certain distance from the surface of Si-NW was greater. A Si-NW Bio-FET modified with specific antibody CD81 on the nanowire was fabricated then used for detection of cell line-derived exosomes, which achieved a low limit of detection (LOD) of 1078 particles/mL in 0.01 × PBS. Furthermore, the Si-NW Bio-FETs modified with specific antibody CD9, CD81 and CD63 respectively, were employed to distinguish exosomes derived from human promyelocytic leukemia (HL-60) cell line in three different states (control group, lipopolysaccharide (LPS) inflammation group, and LPS + Romidepsin (FK228) drug treatment group), which was consistent with nano-flow cytometry. This study provides a highly sensitive method of directly quantifying exosomes without labeling, indicating its potential as a tool for disease surveillance and medication instruction.

Severe/critical COVID-19 early warning system based on machine learning algorithms using novel imaging scores.

BACKGROUND: Early identification of severe/critical coronavirus disease 2019 (COVID-19) is crucial for timely treatment and intervention. Chest computed tomography (CT) score has been shown to be a significant factor in the diagnosis and treatment of pneumonia, however, there is currently a lack of effective early warning systems for severe/critical COVID-19 based on dynamic CT evolution. AIM: To develop a severe/critical COVID-19 prediction model using a combination of imaging scores, clinical features, and biomarker levels. METHODS: This study used an improved scoring system to extract and describe the chest CT characteristics of COVID-19 patients. The study also took into consideration the general clinical indicators such as dyspnea, oxygen saturation, alternative lengthening of telomeres (ALT), and androgen suppression treatment (AST), which are commonly associated with severe/critical COVID-19 cases. The study employed lasso regression to evaluate and rank the significance of different disease characteristics. RESULTS: The results showed that blood oxygen saturation, ALT, IL-6/IL-10, combined score, ground glass opacity score, age, crazy paving mode score, qsofa, AST, and overall lung involvement score were key factors in predicting severe/critical COVID-19 cases. The study established a COVID-19 severe/critical early warning system using various machine learning algorithms, including XGBClassifier, Logistic Regression, MLPClassifier, RandomForestClassifier, and AdaBoost Classifier. The study concluded that the prediction model based on the improved CT score and machine learning algorithms is a feasible method for early detection of severe/critical COVID-19 evolution. CONCLUSION: The findings of this study suggest that a prediction model based on improved CT scores and machine learning algorithms is effective in detecting the early warning signals of severe/critical COVID-19.

Stereoselective Synthesis of Monofluoroalkenylphosphine Oxides via Photoinduced Decarboxylative Coupling of α-Fluoroacrylic Acids with P(O)H Compounds.

Herein, a practical and efficient method for synthesizing monofluoroalkenyl phosphine oxides via photoinduced decarboxylative/dehydrogenative coupling of α-fluoroacrylic acids with phosphine oxides and phosphonates has been developed. Various α-fluoroacrylic acids and P(O)H compounds containing relevant functional groups, including tetrafluorobenzene and pentafluorobenzene, were converted into corresponding products with excellent E-stereoselectivity in satisfactory yields. This method can be extended to achieve the synthesis of monofluoroalkenyl silanes under similar conditions.

[Retinopathy of prematurity screening in 2185 premature infants].

OBJECTIVE: To determine the incidence and risk factors of retinopathy of prematurity (ROP) among premature infants. METHODS: The fundus examination data of 2185 cases of premature infants [birth body weight ≤ 2000 g or gestational age (GA) ≤ 34 weeks] in neonatal intensive care unit of Bayi Children's Hospitals in Beijing between January 2009 and December 2010 were collected and retrospectively analyzed. RESULTS: Of 2185 cases of premature infants (1571 had used supplemental oxygen) received RetCam-II ophthalmoscopy screening, 287 cases developed ROP with the incidence of 13.1% according to the international classification of ROP (ICROP), including 34 cases (11.9%) suffering from zone I, 147 cases (51.2%) from zone II, and 106 cases (36.9%) from zone III. Stage 1, 2 and 3 lesions were 117 cases, 142 cases and 28 cases, accounting for 40.8%, 49.5% and 9.7%, respectively, while stage 4 and stage 5 lesions were not found. Thirty-six cases developed plus disease, accounting for 12.5%. Between ROP and Non-ROP groups, there were significant differences in birth weight (1269.9 ± 380.0) g vs (1479.7 ± 359.3) g vs (1633.9 ± 352.3) g, gestational age (30.6 ± 2.0) g vs (32.4 ± 1.8) W and time of supplemental oxygen [Median 10 d (0 to 71 d) vs 2 d (0 to 36 d)]. Among zone I, II and III groups, there were significant differences in birth weight (1269.9 ± 380.0) g vs (1479.7 ± 359.3) g vs (1633.9 ± 352.3) g, gestational age (29.3 ± 2.2) W vs (30.5 ± 1.9) W vs (31.2 ± 1.8) W and time of supplemental oxygen[Median 14 d (0 to 52 d)vs 10 d (0 to 71 d) vs 8 d (0 to 52 d)] (χ(2) = 257.5, 371.7, 6.695; P < 0.05), while among stage 1, 2 and 3 groups, there were also significant differences in birth weight (1593.3 ± 413.7) g vs (1481.3 ± 336.7) g vs (1325.3 ± 313.7) g, gestational age (30.9 ± 2.0) W vs (30.6 ± 1.9) W vs (29.5 ± 1.7) W and time of supplemental oxygen [Median 8 d (0 to 52 d) vs 11 d (0 to 65 d) vs 12 d (0 to 71 d)] (χ(2) = 230.8, 273.5, 6.695; P < 0.05). In 1004 cases admitted in 2009, 150 developed ROP with the incidence of 14.9%; while in 1181 cases admitted in 2010, 137 developed ROP with the incidence of 11.6%. There was significant differences in the incidence of ROP between these two years (χ(2) = 5.305, P < 0.05). Thirty-eight infants (1.7%) received laser therapy and only 3 infants progressed to stage 4 after laser therapy. Three infants with laser failed stopped progress after vasectomy. Finally, all patients were cured without blindness. CONCLUSIONS: Less birth weight, shorter GA and time of supplemental oxygen are close related to the development of ROP. It is necessary to pay high attention to the screen on premature infants with smaller gestation age, lower birth weight or using oxygen for the reduction or even avoid of blindness.

CuS-PNIPAm nanoparticles with the ability to initiatively capture bacteria for photothermal treatment of infected skin.

Copper sulfide nanoparticles (CuS NPs) have shown great potential in various application fields, especially in biomedical engineering fields. CuS NPs, with the ability to actively capture and kill bacteria and without the worry of biocompatibility, will greatly expand their applications. Herein, a four-arm star thermo-sensitive polyisopropylacrylamide (4sPNIPAm) was used to modify CuS NPs (CuS-PNIPAm NPs). The obtained NPs displayed the controlled release of copper ions and higher photothermal conversion ability in comparison with contrast materials CuS-PEG NPs and CuS NPs. Aggregation of CuS-PNIPAm NPs at above 34°C resulted in capturing bacteria by forming the aggregates of NPs-bacteria. Both Staphylococcus aureus and Escherichia coli co-cultured with CuS-PNIPAm NPs were completely killed upon near-infrared irradiation in minutes. Furthermore, CuS-PNIPAm NPs were verified to be a photothermal agent without toxic effect. In in vivo experiment, the NPs effectively killed the bacteria in the wound and accelerated the process of wound repairment. Overall, photothermal treatment by CuS-PNIPAm NPs demonstrates the ability to actively capture and kill bacteria, and has a potential in the treatment of infected skin and the regeneration of skin tissues. The therapy will exert a far-reaching impact on the regeneration of stubborn chronic wounds.

Epibulbar osseous choristoma: Two case reports.

BACKGROUND: Choristoma is a rare, benign, congenital proliferative tumor, with osseous choristoma being the rarest. Although the tumor is benign, effective identification is needed for its diagnosis and treatment. Here, we report the diagnosis and successful surgical treatment of two patients with osseous choristoma. CASE SUMMARY: Two patients, a young female and young male patient, were found to have a mass on the ocular surface. The tumor presented on the superior temporal bulbar conjunctiva in the first patient and on the upper eyelid in the second patient. Ultrasound biomicroscopy detected a strong echo with clear boundaries covering the lower echo, and computed tomography examination revealed calcification. Both patients underwent surgery, and histopathological evaluation of the mass showed osseous choristoma. They were treated by excision and subsequently cured. CONCLUSION: Osseous choristomas are usually asymptomatic. Our patients were cured immediately after surgery, suggesting that surgical treatment is an effective strategy.

Tilt and decentration with various intraocular lenses: A narrative review.

We find that tilt and decentration of intraocular lens (IOL) commonly cause visual quality deterioration after cataract surgery. Multiple factors affect IOL tilt and decentration in the pre-, mid-, and post-operation phases. Moreover, the tilt and decentration of 1-piece IOL are less correlated with internal ocular HOAs than those of 3-piece IOL. Aspherical IOLs are more sensitive to decentration or tilt than spherical IOLs. Furthermore, the optical performance of toric IOLs with an accurate axis remains stable irrespective of tilt and decentration. The optical quality of asymmetric multifocal IOLs varies significantly after decentration and tilt in different directions. The image quality enhances or deteriorates in the direction of the decentered IOL. An extended depth of focus IOL can achieve good visual acuity in the distant, intermediate, and near range. Additionally, its tilt and decentration have less impact on the vision than bifocal and trifocal IOL. This is the first review that compares the effect of IOL tilt and decentration on image quality for various IOL designs. The result indicates that a deeper understanding of tilt and decentration of various IOLs can help achieve a better visual effect to visually improve refractive cataract surgery.

Changes in Anterior Chamber After Myopic and Hyperopic FS-LASIK.

INTRODUCTION: This study evaluated the changes and explored influential factors in the anterior chamber after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) on the basis of patients with different degrees of myopia, refractive status, and age. METHODS: Patients underwent uneventful FS-LASIK for the treatment of ametropia. All patients with myopia were classified into a low age group (18-40 years) or high age group (> 40 years). Patients in the low age group (18-40 years) were subdivided into myopia and hyperopia groups. According to the preoperative spherical equivalent values, the myopia group was further divided into low myopia, moderate myopia, and high myopia groups. We measured the magnitude of anterior chamber depth (ACD), angle (ACA), volume (ACV), lens rise, central corneal thickness (CCT), and mean pupil power (MPP) of all patients using Sirius (version 3.2, CSO, Italy) before and 3 months post operation. RESULTS: A total of 140 eyes of 87 patients were evaluated. The magnitudes of ACD, ACA, and ACV decreased significantly postoperatively in both low age (P < 0.001, P < 0.001, P < 0.001, respectively) and high age group (P < 0.001, P < 0.001, P < 0.001, respectively) of patients with myopia, while an increasing tendency of ACD (2.85 ± 0.38 mm preoperatively vs 2.89 ± 0.09 mm postoperatively) and ACA (39.16° ± 7.30° preoperatively vs 39.37° ± 7.68° postoperatively) was found in hyperopia. There was no correlation between different degrees of myopia and the changes in the anterior chamber. CONCLUSIONS: Anterior chamber parameters decreased significantly and approximately in the same degree in low and high age groups postoperatively, while an increasing tendency of ACD and ACA was found in hyperopia, indicating that it is probably a corneal magnification effect that influences changes in the anterior chamber.

Cytotoxic Indolocarbazoles From a Marine-Derived Streptomyces Sp. OUCMDZ-5380.

Under the guidance of global natural product social molecular networking, three new indolocarbazoles named streptocarbazoles F-H (1-3), along with staurosporine (4) were isolated from the marine-derived Streptomyces sp. OUCMDZ-5380. Structures of streptocarbazoles F-H were, respectively, determined as N-demethyl-N-hexanoylstaurosporine (1), N-demethyl-N-(2-methyl-3-methoxypyridin-4-yl) staurosporine staurosporine (2), and 4-(N-demethylstaurosporine-N-yl)-1,2-dimethyl-3-methoxypyridinium (3) by spectroscopic analysis and electronic circular dichroism comparison with staurosporine. Compared with staurosporine (4), streptocarbazoles F-H (1-3) showed a selective antiproliferation of the acute myeloid leukemia cell line MV4-11 with the IC50 values of 0.81, 0.55, and 1.88 µM, respectively.

Toughened Hydrogels for 3D Printing of Soft Auxetic Structures.

Materials with negative Poisson's ratio have attracted considerable attention and offered high potential applications as biomedical devices due to their ability to expand in every direction when stretched. Although negative Poisson's ratio has been obtained in various base materials such as metals and polymers, there are very limited works on hydrogels due to their intrinsic brittleness. Herein, we report the use of methacrylated cellulose nanocrystals (CNCMAs) as a macro-cross-linking agent in poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogels for 3D printing of auxetic structures. Our developed CNCMA-pHEMA hydrogels exhibit significant improvements in mechanical properties, which is attributed to the coexistence of multiple chemical and physical interactions between the pHEMA and CNCMAs. Structures printed by using CNCMA-pHEMA hydrogels show auxetic behavior with greatly enhanced toughness and stretchability compared to the hydrogel with a traditional cross-linking agent. Such strong and tough auxetic hydrogels would contribute toward establishing advanced flexible implantable devices such as biodegradable oesophageal self-expandable stents.