High performance production process development and scale-up of an anti-TSLP nanobody

Nanobodies (Nbs) represent a class of single-domain antibodies with great potential application value across diverse biotechnology fields, including therapy and diagnostics. Thymic Stromal Lymphopoietin (TSLP) is an epithelial cell-derived cytokine, playing a crucial role in the regulation of type 2 immune responses at barrier surfaces such as skin and the respiratory/gastrointestinal tract. In this study, a method for the expression and purification of anti-TSLP nanobody (Nb3341) was established at 7 L scale and subsequently scaled up to 100 L scale. Key parameters, including induction temperature, methanol feed and induction pH were identified as key factors by Plackett-Burman design (PBD) and were optimized in 7 L bioreactor, yielding optimal values of 24 °C, 8.5 mL/L/h and 6.5, respectively. Furthermore, Diamond Mix-A and Diamond MMC were demonstrated to be the optimal capture and polishing resins. The expression and purification process of Nb3341 at 100L scale resulted in 22.97 g/L titer, 98.7% SEC-HPLC purity, 95.7% AEX-HPLC purity, 4 ppm of HCP content and 1 pg/mg of HCD residue. The parameters of the scaling-up process were consistent with the results of the optimized process, further demonstrating the feasibility and stability of this method. This study provides a highly promising and competitive approach for transitioning from laboratory-scale to commercial production-scale of nanobodies.

The Effects of Exogenous 2,4-Epibrassinolide on the Germination of Cucumber Seeds under NaHCO3 Stress

This investigation focused on the suppressive impact of varying NaHCO3 concentrations on cucumber seed germination and the ameliorative effects of 2,4-Epibrassinolide (EBR). The findings revealed a negative correlation between NaHCO3 concentration and cucumber seed germination, with increased NaHCO3 concentrations leading to a notable decline in germination. Crucially, the application of exogenous EBR significantly counteracted this inhibition, effectively enhancing germination rates and seed vigor. Exogenous EBR was observed to substantially elevate the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), thereby mitigating oxidative damage triggered under NaHCO3 stress conditions. Additionally, EBR improved enzyme activity under alkaline stress conditions and reduced starch content in the seeds. Pertinently, EBR upregulated genes that were associated with gibberellin (GA) synthesis (GA20ox and GA3ox), and downregulated genes that were linked to abscisic acid (ABA) synthesis (NCED1 and NCED2). This led to an elevation in GA3 concentration and a reduction in ABA concentration within the cucumber seeds. Therefore, this study elucidates that alleviating oxidative stress, promoting starch catabolism, and regulating the GA and ABA balance are key mechanisms through which exogenous EBR mitigates the suppression of cucumber seed germination resulting from alkaline stress.

TROP2-directed nanobody-drug conjugate elicited potent antitumor effect in pancreatic cancer

BACKGROUND

Pancreatic cancer is a highly aggressive malignancy with limited treatment options and a poor prognosis. Trophoblast cell surface antigen 2 (TROP2), a cell surface antigen overexpressed in the tumors of more than half of pancreatic cancer patients, has been identified as a potential target for antibody-drug conjugates (ADCs). Almost all reported TROP2-targeted ADCs are of the IgG type and have been poorly studied in pancreatic cancer. Here, we aimed to develop a novel nanobody-drug conjugate (NDC) targeting TROP2 for the treatment of pancreatic cancer.

RESULTS

In this study, we developed a novel TROP2-targeted NDC, HuNbTROP2-HSA-MMAE, for the treatment of TROP2-positive pancreatic cancer. HuNbTROP2-HSA-MMAE is characterized by the use of nanobodies against TROP2 and human serum albumin (HSA) and has a drug-antibody ratio of 1. HuNbTROP2-HSA-MMAE exhibited specific binding to TROP2 and was internalized into tumor cells with high endocytosis efficiency within 5 h, followed by intracellular translocation to lysosomes and release of MMAE to induce cell apoptosis in TROP2-positive pancreatic cancer cells through the caspase-3/9 pathway. In a xenograft model of pancreatic cancer, doses of 0.2 mg/kg and 1 mg/kg HuNbTROP2-HSA-MMAE demonstrated significant antitumor effects, and a dose of 5 mg/kg even eradicated the tumor.

CONCLUSION

HuNbTROP2-HSA-MMAE has desirable affinity, internalization efficiency and antitumor activity. It holds significant promise as a potential therapeutic option for the treatment of TROP2-positive pancreatic cancer.

Smoke and Spike: Benzo[a]pyrene Enhances SARS-CoV-2 Infection by Boosting NR4A2-Induced ACE2 and TMPRSS2 Expression

Cigarette smoke aggravates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the underlying mechanisms remain unclear. Here, they show that benzo[a]pyrene in cigarette smoke extract facilitates SARS-CoV-2 infection via upregulating angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). Benzo[a]pyrene trans-activates the promoters of ACE2 and TMPRSS2 by upregulating nuclear receptor subfamily 4 A number 2 (NR4A2) and promoting its binding of NR4A2 to their promoters, which is independent of functional genetic polymorphisms in ACE2 and TMPRSS2. Benzo[a]pyrene increases the susceptibility of lung epithelial cells to SARS-CoV-2 pseudoviruses and facilitates the infection of authentic Omicron BA.5 in primary human alveolar type II cells, lung organoids, and lung and testis of hamsters. Increased expression of Nr4a2, Ace2, and Tmprss2, as well as decreased methylation of CpG islands at the Nr4a2 promoter are observed in aged mice compared to their younger counterparts. NR4A2 knockdown or interferon-λ2/λ3 stimulation downregulates the expression of NR4A2, ACE2, and TMPRSS2, thereby inhibiting the infection. In conclusion, benzo[a]pyrene enhances SARS-CoV-2 infection by boosting NR4A2-induced ACE2 and TMPRSS2 expression. This study elucidates the mechanisms underlying the detrimental effects of cigarette smoking on SARS-CoV-2 infection and provides prophylactic options for coronavirus disease 2019, particularly for the elderly population.

Case Report: Analysis of four cases of metastatic bladder masses after radical prostatectomy

Objective

The aim of this study is to investigate the clinical characteristics and diagnostic and therapeutic methods of bladder metastasis after radical prostatectomy and to improve its diagnosis and treatment.

Methods

The clinical data of four patients with bladder metastasis after radical prostatectomy were retrospectively analyzed from January 2011 to December 2021. Three cases suffered from intermittent gross hematuria, and only one case was found to have an elevated prostate-specific antigen (PSA) value. Transurethral resection of bladder tumor was performed in four cases, in which one case also underwent resection of urethral mass. Three cases received endocrine therapy, one of which added intravesical instillation and radiation therapy. Another case received chemotherapy based on comprehensive treatment.

Results

According to the pathological and immunohistochemical results, three cases were acinar adenocarcinoma of the prostate with Gleason score of 9, and all cases were PSA positive and negative for cytokeratin 7 (CK7) and GATA binding protein 3 (GATA-3). One case was small cell neuroendocrine carcinoma of the prostate and was positive for chromogranin A (CGA), synaptophysin (SYN), and cluster of differentiation 56 (CD56). During the follow-up period of 4 to 13 months, one case was lost to follow-up and three cases were alive.

Conclusion

Bladder metastasis after radical prostatectomy is rare, and pathology combined with immunohistochemistry is the gold standard for its diagnosis. Pathological type determines its treatment. Systemic treatment is essential, and local treatment is the most palliative means. Early diagnosis and treatment is significant for better prognosis.

The Clinical Study on Short-Term Efficacy of Pelvic Magnetic Stimulation Combined with Pelvic Muscle Biofeedback on Female Idiopathic Overactive Bladder

Objective

To evaluate the short-term efficacy of pelvic magnetic stimulation combined with pelvic muscle biofeedback on female Idiopathic Overactive Bladder (IOAB).

Methods

96 cases of IOAB females were randomly divided into control group (magnetic stimulation treatment n=48) and observation group (magnetic stimulation with biofeedback n=48). All the patients were dealt with the sacralneuromagnetic stimulation (once, qod), with 5 times in total. Then the patients in observation group were processed with biofeedback (10 times). Overactive Bladder Symptom Score (OABSS), Patients Perception Bladder Condition (PPBC) and Incontinence Quality of Life Scale (I-QOL) were evaluated as the indexes.

Results

The effective rate of control group and observation group respectively were 89.58% and 93.75%. There were significant differences (P=0.67). The OABSS and PPBC of two groups were decreased, I-QOL were increased after treatment (P<0.05). Difference was statistically significant in OABSS three months after treatment between the two groups (P=0.00).The recurrence rate of three months after treatment of the two groups were 18.75% and 6.38% (P=0.04).

Conclusions

Both magnetic stimulation alone and magnetic stimulation with biofeedback were effective and safe in female patients with IOAB. Magnetic stimulation with biofeedback may reduce the recurrence rate and continue to improve the symptoms in a certain extent.

Perfusate Neutrophil Gelatinase-Associated Lipocalin, Kidney Injury Molecular-1, Liver-Type Fatty Acid Binding Protein, and Interleukin-18 as Potential Biomarkers to Predict Delayed Graft Function and Long-Term Prognosis in Kidney Transplant Recipients: A Single-Center Retrospective Study

BACKGROUND Delayed graft function (DGF) caused by ischemia-reperfusion injury is a common pathophysiological process that should be monitored by specific biomarkers in addition to serum creatinine. Thus, this single-center retrospective study aimed to investigate the association between levels of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecular-1 (KIM-1), liver-type fatty acid binding protein (L-FABP), and interleukin-18 (IL-18) in DGF associated with acute kidney injury in kidney transplant recipients (KTRs) and estimated glomerular filtration rate (eGFR) at 3 years post-transplant. MATERIAL AND METHODS A total of 102 KTRs [14(13.7%) of DGF and 88(86.3%) of NON-DGF] were enrolled. DGF was defined as "dialysis is needed within 1 week after kidney transplantation". NGAL, KIM-1, L-FABP, and IL-18 were obtained from perfusate samples of donation-after-cardiac-death (DCD) kidneys, and measured by ELISA. RESULTS Compared to the NON-DGF group, KTRs in the DGF group had a statistically significant increase in levels of NGAL (P<0.001) and KIM-1 (P<0.001). Multiple logistic regression analyses showed that NGAL (OR=1.204, 95% CI 1.057-1.372, P=0.005) and KIM-1 (OR=1.248, CI=1.065-1.463, P=0.006) could be regarded as independent risk factors. The accuracy of NGAL and KIM-1 was 83.3% and 82.1%, respectively, calculated using the area under the receiver operating characteristic curve. Furthermore, the eGFR at 3 years post-transplant had a moderate negative correlation with NGAL (r=-0.208, P=0.036) and KIM-1 (r=-0.260, P=0.008). CONCLUSIONS Our results support those from previous studies showing that perfusate levels of NGAL and KIM-1 are associated with DGF in KTRs and also with reduced eGFR at 3 years post-transplant.

Scintillation Properties of Lanthanide Doped Pb4Lu3F17 Nanoparticles

Inorganic scintillators are of great significance in the fields of medical CT, high-energy physics and industrial nondestructive testing. In this work, we confirm that the Pb₄Lu₃F₁₇: Re (Re = Tb, Eu, Sm, Dy, Ho) crystals are promising candidates for a new kind of scintillator. Detailed crystal structure information is obtained by the Rietveld refinement analysis. Upon X-ray irradiation, all these scintillators exhibited characteristic 4f-4f transitions. The Ce and Gd ions were verified to be useful for enhancing the scintillation intensity via introducing energy transfer processes. The integrated scintillation intensity of the Pb₄Lu₃F₁₇: Tb/Ce is about 16.8% of the commercial CsI (Tl) single crystal. Our results manifested that Pb₄Lu₃F₁₇: Re has potential application in X-ray detection and imaging.

Study on the Identification and Detection of Walnut Quality Based on Terahertz Imaging

Objective: Walnuts have rich nutritional value and are favored by the majority of consumers. As walnuts are shelled nuts, they are prone to suffer from defects such as mildew during storage. The fullness and mildew of the fruit impose effects on the quality of the walnuts. Therefore, it is of great economic significance to carry out a study on the rapid, non-destructive detection of walnut quality. Methods: Terahertz spectroscopy, with wavelengths between infrared and electromagnetic waves, has unique detection advantages. In this paper, the rapid and nondestructive detection of walnut mildew and fullness based on terahertz spectroscopy is carried out using the emerging terahertz transmission spectroscopy imaging technology. First, the normal walnuts and mildewed walnuts are identified and analyzed. At the same time, the image processing is carried out on the physical samples with different kernel sizes to calculate the fullness of the walnut kernels. The THz image of the walnuts is collected to extract the spectral information in different regions of interest. Four kinds of time domain signals in different regions of interest are extracted, and three qualitative discrimination models are established, including the support vector machine (SVM), random forest (RF), and k-nearest neighbor (KNN) algorithms. In addition, in order to realize the visual expression of walnut fullness, the terahertz images of the walnut are segmented with a binarization threshold, and the walnut fullness is calculated by the proportion of the shell and kernel pixels. Results: In the frequency domain signal, the amplitude intensity from high to low is the mildew sample, walnut kernel, and walnut shell, and the distinction between walnut kernel, shell samples, and mildew samples is high. The overall identification accuracy of the aforementioned three models is 90.83%, 97.38%, and 97.87%, respectively. Among them, KNN has the best qualitative discrimination effect. In a single category, the recognition accuracy of the model for the walnut kernel, walnut shell, mildew sample, and reference group (background) reaches 94%, 100%, 97.43%, and 100%, respectively. The terahertz transmission images of the five categories of walnut samples with different kernel sizes are processed to visualize the detection of kernel fullness inside walnuts, and the errors are less than 5% compared to the actual fullness of walnuts. Conclusion: This study illustrates that terahertz spectroscopy detection can achieve the detection of walnut mildew, and terahertz imaging technology can realize the visual expression and fullness calculation of walnut kernels. Terahertz spectroscopy and imaging provides a non-destructive detection method for walnut quality, which can provide a reference for the quality detection of other dried nuts with shells, thus having significant practical value.

High Speed Railway Fastener Defect Detection by Using Improved YoLoX-Nano Model

Rails play a vital role in the bearing and guidance of high-speed trains, and the normal condition of rail components is the guarantee of the operation and maintenance safety. Fasteners are critical components for fixing the rails, so it is particularly important to detect whether they are in a normal state or not. The current rail-fastener detection models have some drawbacks, including poor generalization ability, large model volume and low detection efficiency. In view of this, an improved YoLoX-Nano rail-fastener-defect-detection method is proposed in this paper. The CA attention mechanism is added to the three output feature maps of CSPDarknet and the enhanced feature extraction part of the Path Aggregation Feature Pyramid Network (PAFPN); the Adaptively Spatial Feature Fusion (ASFF) is added after the PAFPN output feature map, which enables the semantic information of the high-level features and the fine-grained features of the bottom layer to be further enhanced. The improved YoLoX-Nano model has improved the AP value by 27.42% on fractured fasteners, 15.88% on displacement fasteners and 12.96% on normal fasteners. Moreover, the mAP value is improved by 18.75%, and it is 14.75% higher than the two-stage model Faster-RCNN on mAP. In addition, compared with YoLov7-tiny, the improved YoLoX-Nano model achieves 13.56% improvement on mAP. Although the improved model increases a certain amount of calculation, the detection speed of the improved model has been increased by 30.54 fps and by 32.33 fps when compared with that of the Single-Shot Multi-Box Detector (SSD) model and the You Only Look Once v3 (YoLov3) model, reaching 54.35 fps. The improved YoLoX-Nano model enables accurate and rapid identification of the defects of rail fasteners, which can meet the needs of real-time detection. Furthermore, it has advantages in lightweight deployment of terminals for rail-fastener detection, thus providing some reference for image recognition and detection in other fields.

Factors Associated with Housing Damage Caused by an EF4 Tornado in Rural Areas of Funing, China

Rural areas are vulnerable to natural disasters and tend to suffer severe losses. An EF4 tornado occurred in Funing on 23 June 2016, killing 99 people, injuring at least 846 people, and destroying more than 2000 houses. Using a multinomial logistic regression model, this study explored the influencing factors between housing damage and variables of building conditions, tornado intensity, and village environmental factors. The results show that 2-story houses and masonry houses were more likely to be slightly damaged or be in a dangerous state. Furthermore, the building area was positively related to houses in two categories: slight damage (SD) and dangerous and requiring immediate repair (DR), indicating that the larger or taller the house, the more severe the damage. In terms of tornado intensity, houses classified as SD were more likely to be hit by EF4 tornados than by EF3 tornados, and houses were damaged more by EF1 or EF2 tornados. This finding demonstrates that the level of housing damage was not strongly correlated with the tornado intensity. Slightly damaged houses exhibited the highest correlation with environmental factors. The proportion of slightly damaged houses was positively correlated with the water area in the village, unlike the proportion of houses in the DR and unable to be repaired (UR) categories. Moreover, the larger the water area of a village, the less housing damage it suffered. These findings provide new insights into minimizing housing damage in wind disasters to improve disaster prevention planning in rural areas.

Successful resection of a huge retroperitoneal venous hemangioma: A case report

BACKGROUND

Venous hemangioma is a benign and non-invasive type of tumor, which is rarely identified due to the absence of clinical manifestations. A retroperitoneal benign tumor is comparatively rare, and hemangioma is exceptional. Because of the different types and locations of hemangioma, presentations are varied; thus, establishing an accurate diagnosis before surgery is challenging.

CASE SUMMARY

A 45-year-old female patient visited our hospital with the complaint of a retroperitoneal mass without symptoms discovered during a medical examination. An abdominal and pelvic computed tomography (CT) revealed a giant hypodense mass that extended from the lower edge of the liver down to the right groin and showed no marked enhancement in the arterial phase of the enhanced CT. On magnetic resonance imaging, the retroperitoneal mass was hyperintense on the T2-weighted image and hypointense on the T1-weighted image. The mass was completely resected and confirmed as a venous hemangioma by pathology.

CONCLUSION

Venous hemangioma is rare in adults, and an accurate diagnosis before surgery is challenging. Surgery is the curative treatment for venous hemangioma, and the definitive diagnosis relies on pathology.

Case report and literature review: Hemophagocytic lymphohistiocytosis in a pregnant woman with systemic lupus erythematosus with Syntaxin 11 gene defect

Hemophagocytic lymphohistiocytosis is an extremely rare occurrence during pregnancy. Early recognition of its signs and symptoms is critical for early intervention, and delays in diagnosis may be life-threatening. A 23-year-old nulliparous woman presented with a persistent fever as high as 39°C with bilateral edema of the lower limbs at 24 weeks of gestation. Typical laboratory findings included pancytopenia, high triglycerides, ferritin, transaminases, bilirubin, and hypoproteinemia. Active systemic lupus erythematosus was diagnosed using an autoimmune work-up and a Systemic Lupus Erythematosus Disease Activity Index 2000 score of 17 points. Her bone marrow aspirate revealed prominent hemophagocytosis; hence, HLH was confirmed. Genetic tests showed mutations in Syntaxin 11 mutations. Considering the potential impact of drugs on the fetus, the patient and her family members chose to terminate the pregnancy through medical induction of labor. Afterwards, her condition improved with immunosuppressive therapy.

Wide space sowing achieved high productivity and effective nitrogen use of irrigated wheat in South Shanxi, China

Wheat (Triticum aestivum L.) is a staple crop worldwide, and its yield has improved since the green revolution, which was attributed to chemical nitrogen (N) fertilizer application. However, regular N application decreases N use efficiency (NUE, the ratio of grain dry matter yield to N supply from soil and fertilizer). Various practices have been implemented to maintain high crop yield and improve NUE. Nowadays, the enhanced sowing method, i.e., wide space sowing (WS), has improved the productivity of wheat crops. However, how the sowing method and N application rate affect N use and yield productivity has not been fully elucidated. Field experiments with treatments using two sowing methods (WS, and drill sowing, DS) and four N application rates (0, 180, 240, and 300 kg ha^-1, represented as N0, N180, N240, and N300, respectively) were conducted from 2017 to 2019. The results showed that grain yield under WS was 13.57-16.38% higher than that under DS. The yield advantage under WS was attributed to an increased ear number. Both the higher stem and productive stem percentage accounted for the increased ear number under WS. Higher total N quantity and larger leaf area index at anthesis under WS contributed to higher dry matter production, resulting in higher grain yield. Higher dry matter production was due to pre-anthesis dry weight and post-anthesis dry weight. The wheat crop under WS had a 12.44-15.00% higher NUE than that under DS. The increased NUE under WS was attributed to higher N uptake efficiency (the ratio of total N quantity at maturity to N supply from soil and fertilizer), which was the result of greater total N quantity. The higher total N quantity under WS was due to both higher pre-anthesis N uptake and post-anthesis N uptake. Remarkably, compared to DS with 240 kg N ha^-1, WS with 180 kg N ha^-1 had almost equal grain yield, dry matter, and total N quantity. Therefore, wheat crops under WS could achieve both high NUE and grain yield simultaneously with only moderate N fertilizer in South Shanxi, China.

Effects of Escin on Oxidative Stress and Apoptosis of H9c2 Cells Induced by H2O2

OBJECTIVE

Myocardial infarction (MI) is a serious heart health problem in the world with a high mortality rate. Our study is mainly aimed at validating the antioxidative stress and antiapoptotic effects of escin in a H2O2-induced cardiomyocyte injury model.

METHODS

H9c2 cells were divided into control group, H2O2 treatment group, and H2O2+escin group. We studied the effect of escin on H9c2 cells and its mechanism by flow cytometry, real-time PCR, CCK-8 assay and Western blot. Cell morphology was observed by cell staining and optical microscopy.

RESULTS

We found that the level of reactive oxygen species (ROS) in the H2O2 treatment group was significantly elevated, while the high level of ROS was significantly reversed after treatment with escin. The protein levels of SOD1, SOD2, Bcl-2, and IκB-α in the H2O2 treatment group were significantly decreased compared with the H2O2+escin group, and the Bax, TNF-α, IL-1β, p65, and IκKα protein expressions were greatly higher than those in the H2O2+escin group. And the results of PCR were also consistent with those. TUNEL-positive cells also decreased significantly when treated with escin. Flow cytometry showed that the percentage of apoptotic cells decreased greatly after treatment of escin. Through IL-1β immunofluorescence, the fluorescence intensity of the H2O2 treatment group was greatly higher compared with that of the control group, but escin reversed this effect.

CONCLUSIONS

These results indicated that escin inhibits H2O2-induced H9c2 cell apoptosis, oxidative stress, and inflammatory responses via the NF-κB signaling pathway.

Preclinical development of a long-acting trivalent bispecific nanobody targeting IL-5 for the treatment of eosinophilic asthma

Background

Eosinophilic asthma is a common subtype of severe asthma with high morbidity and mortality. The cytokine IL-5 has been shown to be a key driver of the development and progression of disease. Although approved monoclonal antibodies (mAbs) targeting IL-5/IL-5R have shown good safety and efficacy, some patients have inadequate responses and frequent dosing results in medication nonadherence.

Results

We constructed a novel trivalent bispecific nanobody (Nb) consisting of 3 VHHs that bind to 2 different epitopes of IL-5 and 1 epitope of albumin derived from immunized phage display libraries. This trivalent IL-5-HSA Nb exhibited similar IL-5/IL-5R blocking activities to mepolizumab (Nucala), an approved targeting IL-5 mAb. Surprisingly, this trivalent Nb was 58 times more active than mepolizumab in inhibiting TF-1-cell proliferation. In primate studies, the trivalent IL-5-HSA Nb showed excellent pharmacokinetic properties, and peripheral blood eosinophil levels remained significantly suppressed for two months after a single dose. In addition, the trivalent IL-5-HSA Nb could be produced on a large scale in a P. pastoris X-33 yeast system with high purity and good thermal stability.

Conclusions

These findings suggest that the trivalent bispecific IL-5-HSA Nb has the potential to be a next-generation therapeutic agent targeting IL-5 for the treatment of severe eosinophilic asthma.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02240-1.

A study of negative-thermal-quenching (Ba/Ca)AlSi5O2N7:Eu2+ phosphors

Phosphor is an important part of the new generation of light-emitting diodes (LEDs), which requires high luminous intensity and high-temperature resistance. In this study, a series of excellent (Ba_1-x-yCa_x)AlSi₅O₂N₇:yEu²⁺ phosphors was developed, which were synthesized by a high-temperature solid-state reaction in a reducing atmosphere. In addition, the crystallinity and luminescence intensity of the samples could be enhanced by some amount of Ca²⁺ substitution. The luminescence intensity was the highest when the Eu²⁺ concentration reached 0.06. Furthermore, the thermal stability of the luminescence was studied in detail. The results were satisfactory, showing that the luminescence intensity of the (Ba_1-xCa_x)AlSi₅O₂N₇:Eu²⁺ phosphors exhibited unique negative-thermal-quenching characteristics both at high (273-473 K) and low (4-273 K) temperatures. And the phosphor combined with UV LED chip and red phosphor Sr₂Si₅N₈:Eu²⁺ can achieve a CRI of 90.4 in white LED application which indicated the (Ba_1-xCa_x)AlSi₅O₂N₇:Eu²⁺ phosphor has potential in LED applications.

Characterizing ammonia emissions from water bodies using dynamic floating chambers

Ammonia (NH₃) is the most important alkaline gas in the atmosphere and plays a central role in atmospheric pollution and the global N cycle. Water bodies receive increasing nitrogen inputs from effluents and atmospheric deposition due to anthropogenic activities and are regarded as the major natural NH₃ and NH₄⁺ sinks. In this work, floating dynamic flux chambers were deployed at four types of freshwater (rivers, large reservoirs, medium-sized reservoirs and ponds) systems and a coastal seawater system to estimate the water-air NH₃ emission fluxes. The NH₃ emission fluxes of rivers (26.4 μg NH₃ m^-2 h^-1) were significantly higher than those of other types of freshwater systems, and the NH₃ flux of offshore water was unexpectedly high (3.9 μg NH₃ m^-2 h^-1). The ammonium content and water temperature were the most important factors driving NH₃ emissions from water bodies. The global NH₃ emissions from water bodies reached 8.88 TgN a^-1, and this value will increase persistently with global warming and water quality deterioration. Water bodies that are relatively eutrophic and directly affected by anthropogenic activities should be considered reservoirs of inputted N instead of permanent sinks.

The complete mitochondrial genome of Tetragonia tetragonioides (Pall.) Kuntze and its phylogenetic implications

The complete mitochondrial genome sequence of Tetragonia tetragonioides (Pall.) Kuntze was assembled and characterized in the present study. The mitochondrial genome was 347,227 bp in length and had a GC content of 43.84%, including 24 transfer RNA (tRNA) genes and three ribosomal RNA (rRNA) genes. Phylogenetic analysis showed that T. tetragonioides was close to and Sesuvium portulacastrum.

Naringenin inhibits autophagy and epithelial-mesenchymal transition of human lens epithelial cells by regulating the Smad2/3 pathway

Cataract is the number one cause of blindness in the world. Fibrosis of the lens is the main cause of cataract. Pathological epithelial-mesenchymal transition (EMT) plays an important role in the development of fibrotic cataract. Inhibition of EMT may be an effective treatment for fibrosis of lens epithelial cells. Naringin (NRG) is one of the major citrus flavonoids, which has many pharmacological properties, including anti-inflammatory and cardioprotective. However, the effect of NRG on cataract induced by abnormal fibrosis of LECs is not clear. Herein, we found NRG inhibited transforming growth factor β2 (TGFβ2)-induced SRA01/04 cell viability. Additionally, NRG inhibited TGFβ2-induced cell migration and EMT. We further noticed that NRG inhibited autophagy and Smad2/3 phosphorylation in LECs. We therefore thought Naringenin inhibited autophagy and EMT of human LECs by regulating the Smad2/3 pathway. NRG could therefore serve as a promising drug for cataract treatment.

Application of the synergistic flame retardant europium hydrotalcite/graphene oxide hybrid material and zinc borate to thermoplastic polyurethane

In this paper, a certain amount of rare earth (europium) was doped into magnesium aluminum salt solution and assembled with graphene oxide (GO) by electrostatic interaction under alkaline conditions. Then, the EuMgAl-LDH/GO hybrid material was synthesized by a hydrothermal method. Its microstructure was analyzed and tested by X-ray diffraction (XRD), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR), the results indicated that the EuMgAl-LDH/GO hybrid material had been successfully prepared. Next, it was mixed with zinc borate and added to a thermoplastic polyurethane (TPU) (thermoplastic polyurethane) matrix by melting blending. The flame retardant and smoke suppression effect of the composite was tested by conical calorimetry. The results showed that, compared with simple TPU, the PHRR (peak heat release rate), THR (total heat release), PSPR (peak smoke production rate) and TSP (total smoke production) value of the composite material decreased by 65.6%, 16.2%, 61% and 37.1%, respectively. Finally, through analysis of the carbon residue after combustion of the TPU composite material, we found that the formed carbon layer is denser and the char yield is greatly improved.

A potent neutralizing nanobody against SARS-CoV-2 with inhaled delivery potential

The coronavirus disease 2019 (COVID‐19) pandemic has become a serious burden on global public health. Although therapeutic drugs against COVID‐19 have been used in many countries, their efficacy is still limited. We here reported nanobody (Nb) phage display libraries derived from four camels immunized with the SARS‐CoV‐2 spike receptor‐binding domain (RBD), from which 381 Nbs were identified to recognize SARS‐CoV‐2‐RBD. Furthermore, seven Nbs were shown to block interaction of human angiotensin‐converting enzyme 2 (ACE2) with SARS‐CoV‐2‐RBD variants and two Nbs blocked the interaction of human ACE2 with bat‐SL‐CoV‐WIV1‐RBD and SARS‐CoV‐1‐RBD. Among these candidates, Nb11‐59 exhibited the highest activity against authentic SARS‐CoV‐2 with 50% neutralizing dose (ND₅₀) of 0.55 μg/ml. Nb11‐59 can be produced on large scale in Pichia pastoris, with 20 g/L titer and 99.36% purity. It also showed good stability profile, and nebulization did not impact its stability. Overall, Nb11‐59 might be a promising prophylactic and therapeutic molecule against COVID‐19, especially through inhalation delivery.

Micro-Nanoscale Characteristics of Pyrite and Its Implications for Gold Mineralization: Two Cases of Gold Deposits in the Youjiang Basin and Southwestern Tianshan Mountains

The mineralogical and compositional characteristics of gold-bearing minerals and the occurrence of gold are not only of great significance to exploring the sources of ore-forming materials and their formation mechanisms but also helpful for designing reasonable beneficiations and smelting schemes and achieving remarkable economic benefits. This paper presents an integrated study on the crystal characteristics, elemental composition and distribution of pyrite (the main gold-bearing minerals), on the basis of electron probe microanalysis (EPMA), scanning electron microscopy (SEM), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and nano-secondary ion mass spectrometry (NanoSIMS). The occurrence of gold in the Shuiyindong gold deposit and Ashawayi gold deposit has been studied by means of microscopy, SEM, and EPMA images, elemental correlations, S-Fe-As ternary diagrams, logAs-logAu diagrams and Au/As ratios. The gold in pyrite of the Shuiyindong deposit is in the form of nano gold inclusions and lattice gold. The gold in pyrite of the Ashawayi deposit dominantly exists in the form of nano gold inclusions or is present as micro-nano gold particles in the cracks or edges of pyrite, some of which can exist as lattice gold. The ore-forming hydrothermal solution of the Shuiyindong gold deposit is mainly underground hot brine, but it may be reformed by a deep magmatic hydrothermal solution or volcanic-subvolcanic hydrothermal solution. The ore-forming hydrothermal solution of the Ashawayi gold deposit is mainly derived from the metamorphic hydrothermal solution formed during the orogenic process, and the ore-forming process or post-mineralization process may be reformed by the leaching of underground hot brine. Finally, the characteristics of ore-forming fluids and evolution of the two types of deposits are determined via pyrite element surface scanning. This paper shows that micro-nanoscale study of gold-bearing pyrite is of great significance to understanding the gold mineralization process and is worth further study.

Using machine learning method to identify MYLK as a novel marker to predict biochemical recurrence in prostate cancer

Aim: This study aims to identify novel marker to predict biochemical recurrence (BCR) in prostate cancer patients after radical prostatectomy with negative surgical margin. Materials & methods: The Cancer Genome Atlas database, Gene Expression Omnibus database and Cancer Cell Line Encyclopedia database were employed. The ensemble support vector machine-recursive feature elimination method was performed to select crucial gene for BCR. Results: We identified MYLK as a novel and independent biomarker for BCR in The Cancer Genome Atlas training cohort and confirmed in four independent Gene Expression Omnibus validation cohorts. Multi-omic analysis suggested that MYLK was a DNA methylation-driven gene. Additionally, MYLK had significant positive correlations with immune infiltrations. Conclusion: MYLK was identified and validated as a novel, robust and independent biomarker for BCR in prostate cancer.

Investigation on the Structure and Fractal Characteristics of Nanopores in High-Rank Coal: Implications for the Methane Adsorption Capacity

The structure and fractal characteristics of nanopores of high-rank coal were investigated using an approach that integrates N₂ adsorption and field emission scanning electron microscopy (FE-SEM). The results indicated that the high-rank coal of the Shanxi Formation has a complex pore-fracture network composed of organic matter pores, mineral-related pores, and microfractures. The pore type of high-rank coal tends to be complicated, and the main pore types are inkbottle pores and open pores, which are more conducive to methane enrichment. The R_o,max has a negative relationship with the total pore volume. In addition, the ash and inertinite contents show a positive correlation with the average pore size (APS), while the fixed carbon content exhibits a negative relationship with the APS. The pore structure of high-rank coal is controlled not only by the degree of metamorphism but also by coal composition, which leads to the variation in pore structure becoming more complicated. With the increase in coal metamorphism, high-rank coal with high amounts of fixed carbon content generally possesses a higher irregularity in pore structure. No obvious relationship was observed between D₂ and the coal components, which indicates that the pore structure, ash content, moisture content and other factors controlled by the metamorphism of coal have different effects on D₂ that lead to this inapparent relationship. A negative relationship exists between adsorption volume and D₁, which indicates that the high irregularity of the pore structure is not conducive to methane absorption and that no obvious correlation exists between the adsorption volume and D₂. In the high-rank coal, the high D₁ value represents the complexity and heterogeneity of the pore structure and represents a low adsorption affinity for methane molecules; in addition, D₂ has no effect on the methane adsorption capacity.

Characteristics of Micro/Nano Pores and Hydrocarbon Accumulation in a Continental Shale Oil Reservoir-A Case Study of the Lucaogou Formation in the Jimsar Sag, Junggar Basin, Northwest China

This paper comprehensively studies the micro- and nanometer-scale pore characteristics and structure of the Lucaogou Formation shale oil reservoir in the Jimsar Sag using high-pressure mercury analysis, field emission scanning electron microscopy and nano-CT scanning technology. In addition, the occurrence states of crude oil in pores are analyzed combined with macro-micro characteristics. The results show that there are various reservoir types; the main reservoir pore structure is on the micron and nanometer levels, with other void spaces including intergranular pores, interparticle dissolution pores, intercrystalline pores and microfissures. Nanopores are generally oil-bearing and mostly in the adsorption state, which changes the traditional understanding that micron pores are the only microscopic pores in the reservoir and confirms that shale oil exists in 'sweet spots' and mud-shale sections of the Lucaogou Formation.

Micro-Nanopore Structure and Fractal Characteristics of Tight Sandstone Gas Reservoirs in the Eastern Ordos Basin, China

The complex pore system in tight sandstone reservoirs controls the storage and transport of natural gas. Thus, quantitatively characterizing the micro-nanopore structure of tight sandstone reservoirs is of great significance to determining the accumulation and distribution of tight gas. The pore structure of reservoirs was determined through polarizing microscopy, scanning electron microscopy (SEM), and the combination of mercury injection capillary pressure (MICP) and nuclear magnetic resonance (NMR) experiments on Late Paleozoic conventional and tight sandstone samples from the Linxing Block, Ordos Basin. The results show that in contrast to conventional sandstone, dissolution pores, with diameters less than 8 μm, are the main contributors to the gas storage space of tight sandstone reservoirs. The pore size distribution derived from the MICP experiment demonstrates that the main peak of tight sandstones corresponds to a pore radius in the range of 247 nm to 371 nm, while the secondary peak usually corresponds to 18 nm. The results of the NMR test illustrate that the T₂ spectra of tight sandstones are unimodal, bimodal and multimodal, and the main NMR peak is highly related to the MICP peak. Fractal theory was proposed to quantitatively characterize the complex pore structure and rough porous surface. The sandstones show fractal characteristics including nanopore fractal dimension D_N obtained from the MICP and large pore fractal dimension D_L obtained from the NMR experiment. Both D_N and D_L are positively correlated with porosity and negatively correlated with permeability, demonstrating that complex and heterogeneous pore structure could increase the gas storage space and reduce the connectivity.

Effect of Composition on the Micropore Structure of Non-Marine Coal-Bearing Shale: A Case Study of Permian Strata in the Qinshui Basin, China

The nanopore network in organic-rich shale plays a key role in shale gas storage and migration, and micropores are an important structural unit in connecting the migration channel. In this study, we selected six non-marine coal-bearing shales from the Qinshui Basin to investigate the effect of composition on micropore structure using X-ray diffraction, total organic carbon (TOC), vitrinite reflectance, and CO₂ adsorption methods. The results indicate that non-marine shale with higher TOC content possesses more micropores, leading to a more complex pore structure and improving the heterogeneity of shale reservoirs. With the increase in TOC content, the micropore surface area and micropore volume clearly increases, which greatly improves the gas storage space in shale reservoirs. The thermal evolution of organic matter promotes the development of micropores to a certain extent in non-marine shale. Clay minerals possess a rough surface and develop more micropores, and their influence on the micropore structure of non-marine shale is relatively strong, while terrestrial quartz exhibits significant micropore development. The obviously positive correlations between micropore volume and kaolinite, chlorite contents in the non-marine shale suggest that kaolinite and chlorite make a certain contribution to micropore volume. The characteristics of micropore structures in coal mainly depend on lithotypes, TOC content, and ash content, while clay content, quartz content, and TOC content are the key factors controlling the formation of micropores in non-marine shale.

[Analysis of Multi-scale Spatio-temporal Differentiation Characteristics of PM2.5 in China from 2011 to 2017]

It is of great significance for joint prevention and control of air pollution to understand the spatial and temporal differentiation characteristics and regional driving factors of PM_2.5 in China. In this study, from a multi-scale perspective, the spatial pattern analysis and geographical detectors are used to explore the spatial and temporal distribution pattern and causes of PM_2.5 pollution in China mainland from 2011 to 2017. The results show that:① the annual average PM_2.5 concentration is relatively stable from 2011 to 2017, and there is no obvious trend. The change characteristics of regional PM_2.5 are similar to those of national PM_2.5, showing a "W" shaped fluctuation. Overall, the order of pollution degree from high to low is:central, eastern, western, and northeastern. ② From the spatial pattern analysis results, we can see that the high-value cluster mainly appears in east China, middle China, and southwest of Xinjiang, while the low-value cluster appears in Qinghai-Tibet, Yunnan, Guizhou, Plateau, and Daxinganling regions. ③ The results of geographic detector analysis show that the population factor is the leading factor nationally; meanwhile, the industrial, energy consumption, and traffic factors all contribute to the distribution pattern of PM_2.5 in varying degrees. Regionally, besides the population factor, the proportion of secondary production and urban green space rate have the greatest impact on the northeast, the industrial smoke and dust and road area in the east, and the total industrial electricity and buses in the central area. The impact of social and economic factors does not significantly affect the PM_2.5 in the western region.

Neonatal hand, foot, and mouth disease due to coxsackievirus A6 in Shanghai

BACKGROUND

Evidence of hand, foot, and mouth disease (HFMD) in neonates is limited. The aim of this study was to evaluate the clinical symptoms, pathogens, possible transmission routes, and prognosis of neonatal HFMD in Shanghai.

METHODS

This was a case-control study based on the HFMD registry surveillance system. All neonates and infected family members were enrolled between 2016 and 2017 in Shanghai. Neonates with HFMD were followed for at least half a year. Detailed questionnaires, medical history, and physical examination were recorded. Routine blood examination, liver and renal function, immunophenotypes of peripheral blood lymphocytes (CD3, CD4, and CD8 T-cells; NK cells), immunoglobulin (Ig) M, IgG, and IgA, and cytokine interleukin (IL-1β, IL-2R, IL-6, IL-8, IL-10, and TNF-α) levels were measured. All rectal swab specimens were collected and genotyped for enterovirus, and phylogenetic analysis based on the VP1 sequences of coxsackievirus A6 (CV-A6) was performed to investigate molecular and evolutionary characteristics. T-test or nonparametric test was used to evaluate the differences. Logistic analysis was applied to calculate the risk of clinical manifestations in the group of HFMD neonates and their paired siblings.

RESULTS

There were 16 neonates among the 12,608 diagnosed patients with HFMD, accounting for 0.13%. All neonatal infections were transmitted by other members of the family, mainly the elder siblings, and were caused by CV-A6. CV-A6 was the emerging and predominant causative agent of HFMD in Shanghai. None of the neonates with HFMD experienced fever, onychomadesis, or severe complications. However, two elder sibling patients showed lethargy, and one developed hypoperfusion. In the elder siblings with HFMD, the proportion of white blood cells was generally higher than in neonates with HFMD. The immunologic function of the neonates with HFMD was basically normal. The levels of inflammatory markers were higher in both neonates and elder siblings with HFMD compared to age-matched controls. The clinical symptoms receded about 1 week after onset. None of the neonates had sequelae.

CONCLUSIONS

In our study, CV-A6 infection in neonates was benign, but had the character of family clustering. Due to the two-child policy in China, elder siblings may be the main route of HFMD transmission.

Reduction-sensitive poly(ethylene glycol)-polypeptide conjugate micelles for highly efficient intracellular delivery and enhanced antitumor efficacy of hydroxycamptothecin

The non-specific biodistribution of traditional chemotherapeutic drugs against tumors is the key factor that causes systemic toxicity and hinders their clinical application. In this study, a reduction-sensitive polymer conjugate micelle was manufactured to achieve tumor-specific targeting, reduce toxic side-effects and improve anti-tumor activity of a natural anti-cancer drug, hydroxycamptothecin (HCPT). Therefore, HCPT was conjugated with methoxy-poly(ethylene glycol)-poly(β-benzyl-L-aspartate) (mPEG-PBLA) by a disulfide bond or succinate bond for the first time to obtain the mPEG-PBLA-SS-HCPT (PPSH) and mPEG-PBLA-CC-HCPT (PPCH) that would form micelles after high-speed agitation and dialysis. The PPSH micelles showed an average particle size of 126.3 nm, a low polydispersity index of 0.209, and a negative surface charge of -21.1 mV zeta potential. Transmission electron microscopy showed the PPSH micelles to have spherical morphology. PPSH had a low critical micelle concentration of 1.29 μg ml^-1 with high dilution stability, storage stability and reproducibility. Moreover, the particle size of the PPSH micelles had no significant change after incubation with rat plasma for 72 h, probably resulting in high long circulation in the blood. The PPSH micelles showed significant reduction sensitivity to glutathione. Their sizes increased by 403.2 nm after 24 h post-incubation, and 87.6% drug release was achieved 48 h post-incubation with 40 mM glutathione solutions. The PPSH micelles showed stronger inhibition of HepG2 cells in vitro and growth of H-22 tumor in vivo than the PPCH and HCPT solutions after intravenous injection. The accumulation of PPSH micelles in the tumor tissue contributed to the high anti-tumor effect with little side-effect on the normal tissues. The reduction-sensitive PPSH micelles were a promising carrier of HCPT and other poorly soluble anti-cancer drugs.

MR defecography in the assessment of anatomic and functional abnormalities in stress urinary incontinence before and after pelvic reconstruction

PURPOSE

Magnetic resonance defecography (MRD) was used to evaluate anatomic and functional pelvic floor disorders in women with stress urinary incontinence (SUI) before and after midurethral sling (MUS) intervention.

METHOD

We performed MRD in both SUI patients and continent controls. Static MR was used to describe the anatomic abnormalities in levator ani muscle and periurethral ligaments (PUL). Dynamic MR was used to depict the function of the urethra and pelvic floor. We compared the MRD parameters between the SUI patients and continent controls before surgery. For SUI patients, dynamic MR images evaluated the functional changes of the urethra and pelvic floor after surgery.

RESULTS

In SUI group, 75.8 % have PUL defects, 65.7 % discontinuity or complete loss of pubococcygeal muscle, as compared to the continent groups (p < 0.01). There was no significant difference between the perimenopausal volunteers and SUI patients in the puborectalis defection (p > 0.05). The dynamic MR showed the urethral hypermobility, functional urethra shortening, bladder neck funneling, urethra opening and cystocele were significantly associated with SUI patients (p < 0.01). Postoperative MR indicated that SUI patients after MUS had a lower risk of bladder funneling and urethral opening at the defection phase (p < 0.01), but no significant difference in urethral hypermobility or pelvic floor prolapse was seen (p>0.05).

CONCLUSIONS

MRD with high-resolution and defecation phases provides a detailed anatomic and functional evaluation of the pelvic floor in female SUI before and after pelvic reconstruction.

Preclinical development of a novel CD47 nanobody with less toxicity and enhanced anti-cancer therapeutic potential

BACKGROUND

CD47, the integrin-related protein, plays an important role in immune resistance and escape of tumor cells. Antibodies blocking the CD47/SIRPα signal pathway can effectively stimulate macrophage-mediated phagocytosis of tumor cells, which becomes a promising approach for tumor immunotherapy. Nanobodies (Nbs) derived from camelid animals are emerging as a new force in antibody therapy.

RESULTS

HuNb1-IgG4, an innovative anti-CD47 nanobody, was developed with high affinity and specificity. It effectively enhanced macrophage-mediated phagocytosis of tumor cells in vitro and showed potent anti-ovarian and anti-lymphoma activity in vivo. Importantly, HuNb1-IgG4 did not induce the agglutination of human red blood cells (RBCs) in vitro and exhibited high safety for hematopoietic system in cynomolgus monkey. In addition, HuNb1-IgG4 could be produced on a large scale in CHO-S cells with high activity and good stability. Also, we established anti-CD47/CD20 bispecific antibody (BsAb) consisted of HuNb1 and Rituximab, showing more preference binding to tumor cells and more potent anti-lymphoma activity compared to HuNb1-IgG4.

CONCLUSIONS

Both of HuNb1-IgG4 and anti-CD47/CD20 BsAb are potent antagonists of CD47/SIRPα pathway and promising candidates for clinical trials.

Chinese Black Truffle-Associated Bacterial Communities of Tuber indicum From Different Geographical Regions With Nitrogen Fixing Bioactivity

It is well known that the microbes associated with truffle fruiting bodies play a very important role during the truffle lifecycle. Tuber indicum, commonly called Chinese black truffle, is a species endemic to Eastern Asia and in the genus of Tuber. Here, we reported the bacterial communities of T. indicum from different geographical regions and described the bacterial diversity from three compartments (soil, ectomycorrhizae and ascocarps) of T. indicum using high-throughput sequencing combined tissue culture. The results revealed that Bradyrhizobium was the dominant genus in fruiting bodies of T. indicum from nine geographical sites in China, and the microbes in T. indicum ascocarps were influenced by geological locations and soil characteristics. More specific bacterial taxa were enriched in the fruiting bodies than in the ectomycorrhizae and soil. In addition, 60 cultural bacteria were isolated from T. indicum fruiting bodies (4 families, 24 genera), and Pseudomonas, Alcaligenes faecalis, Microbacterium, and Arthrobacter were dominant. One of 13 strains that have potential nitrogen-fixation activities was further verified by an acetylene reduction assay (ARA). Together, this research provides new and important data for better understanding of the interaction between truffle and associated microbe and the biology of truffle itself.

A polymeric micelle with an endosomal pH-sensitivity for intracellular delivery and enhanced antitumor efficacy of hydroxycamptothecin

Amphiphilic poly(ethylene glycol)-imino-poly(benzyl-l-aspartate) (PIPA) and poly(ethylene glycol)-poly(benzyl-l-aspartate) (PPA) block copolymers were synthesized as pH-responsive and pH-nonresponsive copolymers, respectively. Polymer micelles were fabricated by the film dispersion method, and hydroxycamptothecin (HCPT) was physically encapsulated into the micelles. The average diameter of the HCPT-loaded PIPA micelles (PIPAH micelles) was approximately 230 nm, which was slightly smaller than that of the HCPT-loaded PPA micelles (PPAH micelles, approximately 260 nm). The drug-loading content and encapsulation efficiency of the PIPAH micelles (3.33% and 68.89%, respectively) were slightly higher than those of the PPAH micelles (2.90% and 59.68%, respectively). The PIPAH micelles exhibited better colloid stability, storage stability, and plasma stability than the PPAH micelles. Drug release from the PIPAH micelles with imino groups was pH dependent, and more than 75% or 65% of the loaded HCPT was released within 24 h in weakly acidic media (pH 5.0 or 6.0, respectively). An in vitro cell assay demonstrated that the pH-sensitive micelles exhibited potent suppression of cancer cell proliferation and little cytotoxicity on normal cells. Additionally, these micelles could be efficiently internalized by the tumor cells through macropinocytosis- and caveolin-mediated endocytotic pathways. HCPT-loaded micelles had longer circulation time than the HCPT solution in a pharmacokinetic study. In vivo antitumor experiments indicate that the PIPAH micelles had better antitumor efficacy than the pH-insensitive PPAH micelles and the HCPT solution. Therefore, the pH-responsive PIPAH micelles have great potential for high-efficiency delivery of HCPT. STATEMENT OF SIGNIFICANCE: In this study, a new type of pH-responsive amphiphilic copolymer, poly(ethylene glycol)-imino-poly(benzyl-l-aspartate) (PIPA) block copolymer, was synthesized. This copolymer had then self-assembled to form nanomicelles for tumor intracellular delivery of hydroxycamptothecin (HCPT) for the first time. In in vitro test, the PIPAH micelles exhibited adequate stability and pH-dependent drug release. To one's excitement, the PIPAH micelles exhibited better antitumor efficacy and biosafety than the pH-insensitive micelles (PPAH) and the HCPT solution in in vitro and in vivo antitumor experiments. Therefore, the pH-responsive micelles in this study have significant potential to be used for high-performance delivery of HCPT and potentially for the targeted delivery of other cancer therapeutic agents. The polymer designed in this study can be used as a carrier of poorly soluble drugs or other active ingredients.

Mesoporous Silica Nanoparticles as a Prospective and Promising Approach for Drug Delivery and Biomedical Applications

Background:

With the development of nanotechnology, nanocarrier has widely been applied in such fields as drug delivery, diagnostic and medical imaging and engineering in recent years. Among all of the available nanocarriers, mesoporous silica nanoparticles (MSNs) have become a hot issue because of their unique properties, such as large surface area and voidage, tunable drug loading capacity and release kinetics, good biosafety and easily modified surface.

Objective:

We described the most recent progress in silica-assisted drug delivery and biomedical applications according to different types of Cargo in order to allow researchers to quickly learn about the advance in this field.

Methods:

Information has been collected from the recently published literature available mainly through Title or Abstract search in SpringerLink and PubMed database. Special emphasis is on the literature available during 2008-2017.

Results:

In this review, the major research advances of MSNs on the drug delivery and biomedical applications were summarized. The significant advantages of MSNs have also been listed. It was found that the several significant challenges need to be addressed and investigated to further advance the applications of these structurally defined nanomaterials.

Conclusion:

Through approaching this review, the researchers can be aware of many new synthetic methods, smart designs proposed in the recent year and remaining questions of MSNs at present.

Chemical Composition and Antioxidant Activity of Tuber indicum from Different Geographical Regions of China

Tuber indicum, an endemic truffle species in eastern Asian, is an edible mushroom that is both an important export and widely distributed across China. Many existing studies on truffles focus on analyzing their taxonomy, population genetics, volatile organic compounds and artificial cultivation of the truffles, while little information is available about their nutrient composition and pharmacological activity, especially the relationship between chemical composition in ascocarps and their geographic distributions. This study presents a comprehensive investigation of the chemical composition of T. indicum, including free sugars, fatty acids, organic acids, phenolic acids, flavonoids, and polysaccharides, and tracks the antioxidant activity of T. indicum ascocarps collected from five geographical regions of four provinces in P. R. China: Hebei, Tibet, Yunnan, and Liaoning province. Our results showed that T. indicum collected from Qujing, Yunnan province, possessed the highest amount of free sugars (23.67 mg/g dw), total flavonoids (2.31 mg/g dw), total phenolics (4.46 mg/g dw) and the highest DPPH and ABTS radical-scavenging activities. The amount of water-soluble polysaccharides was the highest (115.24 mg/g dw) in ascocarps from Tibet, the total organic acids was the highest (22.073 mg/g dw) in ascocarps from Gongshan, and polyunsaturated fatty acids were most abundant in those from Hebei province. This study reveals that the quantity of chemical compounds in T. indicum varies by geographical origin. Detecting differences in chemical composition may provide important data for understanding the relationship between environmental factors and truffle formation, as well as quality evaluation of the commercial species T. indicum throughout China.

Development of a multiplex PCR assay based on the pilA gene sequences to detect different types of Acidovorax citrulli

Bacterial fruit blotch (BFB) of cucurbits, caused by Acidovorax citrulli, is a major threat to commercial watermelon and melon production worldwide. At present, there are at least two genetically distinct sub-populations (group I and II) of A. citrulli that differ in host preference among cucurbit species and copper sensitivity. In this study, we analyzed the pilA gene sequences of 103 A. citrulli strains from China and other countries. Based on these data, we classified all tested A. citrulli strains into three types. The pilA-based type 1 strains in this study coincided with the previously established group I strains; while the type 2 strains coincided with group II strains. Ten strains that did not cluster with group I or II strains were classified into a new type, designated type 3. Based on differences in pilA sequences, we designed a multiplex PCR assay to distinguish the three A. citrulli pilus types. This multiplex PCR assay has proven to be viable for strain typing of 139 A. citrulli strains and for the detection of this pathogen in artificially inoculated seeds and leaves and naturally infected leaves and fruits. This assay proved to be rapid, accurate, reliable and applicable for early distinction of A. citrulli types associated with BFB epidemics. It may also inform the judicious and environmentally sound use of bactericides, especially copper-based compounds.

Application of 640-slice CT wide-detector volume scan in low-dose CT pulmonary angiography

BACKGROUND

Computed tomography (CT) pulmonary angiography (CTPA) examination has been frequently applied in detecting suspected pulmonary embolism (PE). How to reduce radiation dose to patients is also of concern.

OBJECTIVE

To assess the value of using 640-slice CT wide-detector volume scan with adaptive statistical iterative reconstruction (ASIR) algorithm in low-dose CTPA.

METHODS

Fifty-eight patients who performed with CTPA were divided into two groups randomly. In the first experimental group (n = 30), ASIR combined with volume scan were performed on the patients, while in the second conventional group (n = 28), patients received ASIR combined with conventional spiral scan. General data including age and body mass index, image quality, pulmonary arterial phase, and radiation dose were analyzed by t test in the two groups.

RESULTS

In both groups, all images revealed the 5-order or higher pulmonary arterial branches and fully met the needs for clinical diagnosis. There was no statistical difference in general data between the two groups. In terms of pulmonary phase accuracy, compared with the conventional group, images at pulmonary arterial phase could be captured more accurately in the experimental group. CTDI in the experimental group decreased by 30% compared with that in the conventional group. The actual radiation dose in the experimental group was 1.5 mSv, which is reduced by 53% compared to that in the conventional group.

CONCLUSIONS

Compared with the conventional spiral scan, using 640-slice CT volume scan with ASIR in CTPA is more accurate in scanning phase and has lower radiation dose. There is no significant difference in image quality between the two groups.

Wide-detector CT combined iterative reconstruction in pediatric low-dose scan of the paranasal sinus

BACKGROUND

Computed tomography (CT) is considered a standard modality for imaging the paranasal sinus (PS), but increasingly radiation dose is of concern, especially in children.

OBJECTIVE

This study aims to investigate the feasibility of using a 320-detector CT scanner with a 16 cm wide-detector combined with iterative reconstruction (IR) algorithm to further reduce radiation dose when scanning the PS.

METHODS

A total of 90 children who underwent CT of the PS were randomly allocated into three groups namely, (1) the experimental group using low-dose wide-detector scan (n = 30, 9±4 years); (2) low-dose helical group (n = 30, 9±4 years); and (3) pediatric conventional group (n = 30, 8±4 years). Statistical software SPSS 19.0 was used for one-way ANOVA analysis of the general data (age, BMI), image quality, and radiation dose. Multiple comparisons of data without homogeneity of variance were analyzed by Bonferroni test and Tamhane's test.

RESULTS

All patients underwent successful CT examinations. No significant differences in the general data and image quality evaluation were detected between three groups (all P values > 0.05). CTDIvol and DLP were 2.87 mGy and 32.58 mGy·cm in the experimental group, 4.92 mGy and 70.84 mGy·cm in the low-dose helical group, and 9.95 mGy and 131.83 mGy·cm in the conventional group, respectively, which were significantly different among these three groups as indicated by multiple comparisons (all P values < 0.05). In the experimental group, the effective radiation dose was 0.07 mSv, which was reduced by 76% and 56% comparing to the conventional group and the low-dose helical group, respectively.

CONCLUSIONS

The 320-detector CT scanner equipped with the wide-detector combined with IR can further reduce radiation dose, while maintaining good image quality comparing to the low-dose helical or pediatric modes.

Osteopontin alters DNA methylation through up-regulating DNMT1 and sensitizes CD133+/CD44+ cancer stem cells to 5 azacytidine in hepatocellular carcinoma

BACKGROUND

In hepatocellular carcinoma (HCC), CD133+/CD44+ cells are one subgroup with high stemness and responsible for metastatic relapse and resistance to treatment. Our previous studies have demonstrated that osteopontin (OPN) plays critical roles in HCC metastasis. We further investigated the molecular mechanism underlying the role of OPN in regulating the stemness of HCC epigenetically and explored possible targeting strategy.

METHODS

CD133+/CD44+ subgroup sorting from HCC cell lines and HCC tissues was used to investigate the effects of OPN knockdown on stemness. iTRAQ and MedIP-sequencing were applied to detect the protein profile and epigenetic modification of CD133+/CD44+ subgroup with or without OPN knockdown. The antitumor effects of 5 Azacytidine were examined in cultured HCC cells and patient derived xenograft (PDX) models.

RESULTS

OPN was accumulated in CD133+/CD44+ subgroup of HCC cells. Knocking down OPN significantly inhibited the sphere formation and stemness-related genes expression, and delayed tumor initiation of CD133+/CD44+ subgroup of HCC cells. Employing MedIP-sequencing, dot blot and iTRAQ analyses of CD133+/CD44+ SCR and CD133+/CD44+ shOPN cells, we found that OPN knockdown leaded to reduction in DNA methylation with particular enrichment in CGI. Meanwhile, DNA (cytosine-5)-methyltransferase 1 (DNMT1), the main methylation maintainer, was downregulated via proteomics analysis, which mediated OPN altering DNA methylation. Furthermore, DNMT1 upregulation could partially rescue the properties of CD133+/CD44+ shOPN cells. Both in vitro and in vivo assays showed that CD133+/CD44+ cells with high OPN levels were more sensitive to DNA methylation inhibitor, 5 Azacytidine (5 Aza). The above findings were validated in HCC primary cells, a more clinically relevant model.

CONCLUSIONS

OPN induces methylome reprogramming to enhance the stemness of CD133+/CD44+ subgroup and provides the therapeutic benefits to DNMT1 targeting treatment in HCC.

Osteopontin promotes epithelial-mesenchymal transition of hepatocellular carcinoma through regulating vimentin

Our previous studies have found that osteopontin (OPN) is a promoter for hepatocellular carcinoma (HCC) progression. However, the molecular mechanism by which OPN enhances HCC metastasis remains elusive. Epithelial-mesenchymal transition (EMT) of cancer cells plays a pivotal role in promoting metastatic process. In this study, we demonstrated that OPN promotes HCC metastasis by inducing an EMT-like, more aggressive cellular phenotype in vitro and in vivo. Furthermore, OPN was identified to interact with vimentin by reciprocal OPN and vimentin immunoprecipitation as well as co-immunofluorescence examination. By using deletion mutants, we found that the residues between 246 and 406 in vimentin are required for binding to OPN. Importantly, OPN significantly increased vimentin stability through inhibition of its protein degradation. Knockdown of vimentin neutralized the EMT induced by OPN both in vitro and in vivo. Moreover, a significant correlation between OPN and vimentin levels was found in clinical HCC specimens and their combination had a worse prognosis with shorter overall survival (OS) and time to recurrence (TTR). In multivariate analysis, OPN and their combination were demonstrated to be independent prognostic indicators for OS and TTR of HCC patients. Collectively, this study indicates that OPN can induce EMT of HCC cells through increasing vimentin stability, which provides more in-depth understanding about the molecular mechanisms of OPN in promoting HCC metastasis and opens tantalizing therapeutic possibilities in HCC.