A laser-engraved wearable gait recognition sensor system for exoskeleton robots.

As a reinforcement technology that improves load-bearing ability and prevents injuries, assisted exoskeleton robots have extensive applications in freight transport and health care. The perception of gait information by such robots is vital for their control. This information is the basis for motion planning in assistive and collaborative functions. Here, a wearable gait recognition sensor system for exoskeleton robots is presented. Pressure sensor arrays based on laser-induced graphene are developed with flexibility and reliability. Multiple sensor units are integrated into an insole to detect real-time pressure at key plantar positions. In addition, the circuit hardware and the algorithm are designed to reinforce the sensor system with the capability of gait recognition. The experimental results show that the accuracy of gait recognition by the proposed system is 99.85%, and the effectiveness of the system is further verified through testing on an exoskeleton robot.

Nanochemistry of gold: from surface engineering to dental healthcare applications.

Advancements in nanochemistry have led to the development of engineered gold nanostructures (GNSs) with remarkable potential for a variety of dental healthcare applications. These innovative nanomaterials offer unique properties and functionalities that can significantly improve dental diagnostics, treatment, and overall oral healthcare applications. This review provides an overview of the latest advancements in the design, synthesis, and application of GNSs for dental healthcare applications. Engineered GNSs have emerged as versatile tools, demonstrating immense potential across different aspects of dentistry, including enhanced imaging and diagnosis, prevention, bioactive coatings, and targeted treatment of oral diseases. Key highlights encompass the precise control over GNSs' size, crystal structure, shape, and surface functionalization, enabling their integration into sensing, imaging diagnostics, drug delivery systems, and regenerative therapies. GNSs, with their exceptional biocompatibility and antimicrobial properties, have demonstrated efficacy in combating dental caries, periodontitis, peri-implantitis, and oral mucosal diseases. Additionally, they show great promise in the development of advanced sensing techniques for early diagnosis, such as nanobiosensor technology, while their role in targeted drug delivery, photothermal therapy, and immunomodulatory approaches has opened new avenues for oral cancer therapy. Challenges including long-term toxicity, biosafety, immune recognition, and personalized treatment are under rigorous investigation. As research at the intersection of nanotechnology and dentistry continues to thrive, this review highlights the transformative potential of engineered GNSs in revolutionizing dental healthcare, offering accurate, personalized, and minimally invasive solutions to address the oral health challenges of the modern era.

Prediction of the risk of severe small bowel obstruction and effects of Houpu Paiqi mixture in patients undergoing surgery for small bowel obstruction.

AIM: Small bowel obstruction is a common condition that requires emergency surgery. Slow recovery of bowel function after surgery or the occurrence of one or more complications can exacerbate the disease and result in severe small bowel obstruction (SSBO), significantly impacting recovery. It is characterized by a failure to regain enteral nutrition promptly, requiring long-term intensive care. Therefore, it is necessary to identify factors that predict SSBO, to allow early intervention for patients likely to develop this condition. METHODS: Of the 260 patients who underwent emergency or elective surgery for small bowel obstruction between January 2018 and December 2022, 45 developed SSBO. The least absolute shrinkage and selection operator regression model was applied to optimize factor selection and multivariable logistic regression analysis was used to construct a predictive model. The performance and clinical utility of the nomogram were determined and internal validation was conducted. In addition, the effects of the Houpu Paiqi mixture on postoperative recovery were analyzed by comparing the clinical data of 28 patients who were treated with the mixture and 61patients who did not receive it. RESULTS: The predictors included in the prediction nomogram were age, peritonitis, intestinal resection and anastomosis, complications, operation time, Acute Physiology and Chronic Health Evaluation II score, white blood cell count, and procalcitonin level. The model had an area under the receiver operating characteristic curve of 0.948 (95% confidence interval: 0.814-0.956). Decision curve analysis demonstrated that the SSBO risk nomogram had a good net clinical benefit. In addition, treatment with the Houpu Paiqi mixture reduced postoperative exhaust time, postoperative defecation time, time to first postoperative liquid feed, and length of stay in hospital. CONCLUSIONS: We developed a nomogram that can assist clinicians in identifying patients at greater risk of SSBO, which may aid in early diagnosis and intervention. Additionally, we found that the Houpu Paiqi mixture promoted postoperative recovery.

Possible Mechanism and Treatment Results of Combined Pediatric Fractures of the Humeral Lateral Condyle and Ipsilateral Ulnar Olecranon.

OBJECTIVE: Combined fractures of the lateral condyle of the humerus and the ipsilateral ulnar olecranon are rarely seen in children. Therefore, the mechanism and suitable treatments remain debatable. This study describes the possible mechanism of combined humeral lateral condyle and ipsilateral ulnar olecranon fractures and presents the treatment results. METHODS: Children diagnosed with combined fractures of the humeral lateral condyle and ipsilateralulnar olecranon from July 2010 to July 2020 were retrospectively analyzed. Humeral lateral condyle fractures were treated with open reduction and internal fixation with bioabsorbable pins. Ulnar olecranon fractures were treated with closed reduction and percutaneous pinning with K-wires for Mayo type IA fractures and with tension-band wiring or a locking plate for Mayo type IIA fractures. The postoperative function and appearance of the elbow were evaluated using the Flynn criteria and Mayo Elbow Performance Score (MEPS) at follow-up. RESULTS: The cohort comprised 19 patients aged from 4 to 11 years. Bony compression and avulsion by attached muscles and ligaments may be the leading factors causing the combined injuries, as the children fell with an outstretched and supinated elbow. The average follow-up time was 33 months. High MEPS of >90 indicated that good to excellent results were obtained without complications. CONCLUSIONS: This study proposed a reasonable hypothesis for the mechanism of combined humeral lateral condyle and ipsilateral ulnar olecranon fractures in children. Satisfactory outcomes were achieved with bioabsorbable pins for lateral condyle fractures and closed reduction and percutaneous pinning with K-wires, tension-band wiring, or locking plate for olecranon fractures.

Extraction of impacted mandibular third molars in close proximity to the inferior alveolar canal with coronectomy-miniscrew traction to avoid nerve injury.

OBJECTIVES: Extraction of impacted mandibular third molars (IMTMs) is the most common surgery performed in the Department of Oral and Maxillofacial Surgery. Inferior alveolar nerve (IAN) injury is a rare but severe complication, and the risk is significantly higher in cases of IMTM near the inferior alveolar canal (IAC). The existing surgical method to extract such IMTMs is either not safe enough or is time-consuming. A better surgical design is needed. MATERIALS AND METHODS: From August 2019 to June 2022, 23 patients underwent IMTM extraction by Dr. Zhao at Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, and were found to have IMTMs in close proximity to the IAC. Due to high IAN injury risk, these patients underwent coronectomy-miniscrew traction to extract their IMTMs. RESULTS: The time between coronectomy-miniscrew insertion and complete removal of the IMTM was 32.65 ± 2.110 days, which was significantly shorter than that of traditional orthodontic traction. Two-point discrimination testing revealed no IAN injury, and no injury was reported by patients during follow-up. Other complications, such as severe swelling, severe bleeding, dry socket, and limited mouth opening, were not observed. Postoperative pain levels were not significantly higher in the coronectomy-miniscrew traction group than in the traditional IMTM extraction group. CLINICAL RELEVANCE: For IMTMs that are in close proximity to the IAC and must be extracted, coronectomy-miniscrew traction is a novel approach to minimize the risk of IAN injury in a less time-consuming way with a lower possibility of complications.

The safety and efficacy for the treatment of alectinib in a women with ALK-positive lung cancer delivered a healthy male neonate throughout Pregnancy: A case report.

The incidence of lung cancer in pregnancy is increasing because of an increase in cigarette smoking among young women, air pollution, and advanced maternal age. This is the third case report of a woman with metastatic anaplastic lymphoma kinase (ALK)-positive lung adenocarcinoma treated with alectinib during pregnancy. The patient was diagnosed with lung cancer at 26 weeks' gestation. Her condition rapidly progressed to disseminated intravascular coagulation accompanied by hypoxemia. After 5 days of treatment with alectinib 600 mg twice daily and best supportive care, the patient's symptoms quickly resolved. She delivered a healthy male newborn at 39 weeks' gestation. At birth, the alectinib concentration was 4.3 times higher in maternal plasma than that in newborn plasma (299.0 vs 69.2 ng/mL). The concentrations of alectinib in the amniotic fluid and the placenta were 27.3 ng/mL and 1136.25 ng/g, respectively. The alectinib concentration in the maternal milk (152 ng/mL) indicated that this drug could be excreted through the breast milk. At 12 months after the diagnosis, the mother had recovered well, and no developmental anomalies were observed in the infant.

Small incision reduction and external fixation for the treatment of delayed over fourteen days supracondylar humeral fractures in children.

Background: Supracondylar humeral fractures (SHF) are the most common type of fracture occurring at the distal humerus in children. In patients with delayed presentation of SHF, closed reduction is challenging to achieve with traditional reduction maneuvers. This study aimed to report the clinical results of pediatric SHF delayed over 14 days treated by closed reduction with a minimally invasive technique and external fixation and evaluate the efficacy of this technique. Methods: Between October 2010 and September 2018, children with delayed presentation of SHF over 14 days were retrospectively included in this study. The patients received closed reduction with a minimally invasive technique followed by external fixation. The demographics and radiographic data were collected. The Mayo Elbow Performance Score (MEPS) and the Flynn criteria were used to evaluate the clinical outcomes of treatments. Results: A total of 11 children (aged 4-13 years) with delayed presentation (range, 14-22 days) were recruited. They received surgery using closed reduction with a minimally invasive technique followed by external fixation. None of the surgery was done with the open method. After surgery, the patients' carrying angle returned to normal. The radiological union was evident in 8 to 12 weeks in all fractures without complications. Every patient had a good to excellent score on the MEPS and the Flynn criteria. Conclusions: The results of this series indicated a satisfactory outcome in children with delayed more than 14 days of supracondylar humeral fractures. The closed reduction with a minimally invasive technique followed by external fixation is an alternative treatment for such injury.

Biodegradable and conventional microplastics posed similar toxicity to marine algae Chlorella vulgaris.

It has been demonstrated that some conventional microplastics (CMPs) have toxicities to organisms, however, whether biodegradable microplastics (BMPs) have similar potential risks to marine ecosystems remains to be elucidated. Therefore, this study aimed to investigate i) the effects of CMPs (i. e., micro-sized polyethylene (mPE) and polyamide (mPA)) on marine algae Chlorella vulgaris; and ii) the potential effects of BMPs (i.e., micro-sized polylactic acid (mPLA) and polybutylene succinate (mPBS)) on C. vulgaris. The results showed that either CMPs or BMPs inhibited the growth of microalgae compared with the control. The maximum inhibition ratio of the four types of MPs on C. vulgaris were 47.24% (mPE, 1 000 mg/L), 40.36% (mPA, 100 mg/L), 47.95% (mPLA, 100 mg/L) and 34.25% (mPBS, 100 mg/L), respectively. Among them, mPLA showed the strongest inhibitory effect on the growth of C. vulgaris. Interestingly, the MPs can stimulate the contents of pigments (e.g., chlorophyll a, chlorophyll b, and carotenoid), which may be acted as cellular defense to the stress induced by MPs. The results also showed that MPs stimulated the production of EPS. Under the investigated condition, the strongest inhibition on C. vulgaris was induced by mPLA, and followed by mPE, mPA, and mPBS. It was found that the factors such as the physicochemical properties of MPs (e.g., shading effect, the roughness of surface, the increase in potential), the chemical changes (i.e., the release of additives, the increase of oxidative stress) contributed to the inhibitory effects of MPs on microalgae, but the deciding factor remains to be further systematically explored.

Meta-Teacher For Face Anti-Spoofing.

Face anti-spoofing (FAS) secures face recognition from presentation attacks (PAs). Existing FAS methods usually supervise PA detectors with handcrafted binary or pixel-wise labels. However, handcrafted labels may are not the most adequate way to supervise PA detectors learning sufficient and intrinsic spoofing cues. Instead of using the handcrafted labels, we propose a novel Meta-Teacher FAS (MT-FAS) method to train a meta-teacher for supervising PA detectors more effectively. The meta-teacher is trained in a bi-level optimization manner to learn the ability to supervise the PA detectors learning rich spoofing cues. The bi-level optimization contains two key components: 1) a lower-level training in which the meta-teacher supervises the detector's learning process on the training set; and 2) a higher-level training in which the meta-teacher's teaching performance is optimized by minimizing the detector's validation loss. Our meta-teacher differs significantly from existing teacher-student models because the meta-teacher is explicitly trained for better teaching the detector (student), whereas existing teachers are trained for outstanding accuracy neglecting teaching ability. Extensive experiments on five FAS benchmarks show that with the proposed MT-FAS, the trained meta-teacher 1) provides better-suited supervision than both handcrafted labels and existing teacher-student models; and 2) significantly improves the performances of PA detectors.

Occurrence and spatial distribution of microplastics, and their correlation with petroleum in coastal waters of Hainan Island, China.

In this study, the distribution, abundance, morphology, and composition of microplastics (MPs) in surface seawater and sediment of Hainan Island were systematically investigated. Seawater and sediment samples were collected from six functional zones, including harbor, industrial district, sparsely populated area, tourist area, residential area, and aquaculture area. The abundance of MPs in seawater was 0.46-19.32 items/L, with an average of 2.59 ± 0.43 items/L, which were similar to those detected in the South China Sea (e.g., Nansha (1.25-3.20 items/L) and Xisha (2.57 ± 1.78 items/L)). The highest level was detected in Qinglan Bay Estuary, and the lowest was in Sanya West Island. The abundance of MPs in sediment was 41.18-750.63 items/kg, with an average of 372.47 ± 62.10 items/kg; the highest concentration was detected at Tanmen Port, and the lowest was in Lingao sea area. It was detected that the MPs with smaller size exhibited a higher concentration in seawater. MPs were commonly black and white, and predominantly linear and fragmented in shape. Polyethylene terephthalate (PET) was the dominant polymer, which might be derived from laundry wastewater. The petroleum concentration was 0.02-0.21 mg/L in the investigated area, with harbors being the most severely polluted areas. Furthermore, this study also found that MPs pollution was positively correlated with petroleum in seawater, indicating similarities between MPs and petroleum-based sources of pollution. This study identifies the contamination and characteristics of MPs and their correlation with petroleum in Hainan Island, the biggest island in the South China Sea, providing important data for further research on protecting marine ecosystems.

Microplastics aged in various environmental media exhibited strong sorption to heavy metals in seawater.

To date, the degradation of microplastics (MPs; <5 mm) in different environments, particularly their adsorption characteristics for coexisted metal pollutants remains to be elucidated. Thus, this study investigated the effects of aging MPs, including polyamide (mPA), polyethylene terephthalate (mPET), polystyrene (mPS), and polyvinyl chloride (mPVC) for 3 months under UVA irradiation in four environmental media (air, seawater, sand, and soil) and adsorption of heavy metals (Cu, Cd) onto seawater-aged mPS and mPVC. The results showed that surface morphological changes, including cracks, oxidized particles, and wrinkles, appeared on aged MPs. The heavy metal adsorption capacity decreased in the order aged mPVC > aged mPS > unaged mPS > unaged mPVC, and the Cu2+ and Cd2+ ions competed for active adsorption sites on the MPs surfaces. Overall, the aging environment affected the physical and chemical properties of MPs and the aging of MPs enhanced their adsorption of coexisting metals tested.

Accuracy of cone-beam computed tomography for the evaluation of mandible invasion by oral squamous cell carcinoma.

BACKGROUND: For patients with oral squamous cell carcinoma (OSCC), accurate evaluation of mandible invasion and resection with appropriate boundaries are important for preserving the structure and function of the mandible and preventing local recurrence. Although cone-beam computed tomography (CBCT), which has high spatial resolution, is now widely used in the diagnosis of oral and maxillofacial bone lesions, no studies have systematically evaluated the accuracy of CBCT for evaluating the presence of bone invasion, the boundaries of bone invasion and the presence of nerve invasion. Therefore, this study aimed to systemically explore the accuracy of CBCT in the preoperative assessment of mandibular invasion by OSCC. METHODS: Thirty mandibular specimens from OSCC patients were collected in this study. The samples were marked and subjected to CBCT examination. Hematoxylin-eosin staining was used for histopathological assessment sed as the gold standard. The evaluation included the presence of bone invasion, the boundaries of bone invasion and the presence of nerve invasion. The CBCT and histopathological boundaries of bone invasion were delineated and merged to compare and calculate the deviation of CBCT in boundary evaluation. RESULTS: The accuracy of CBCT in evaluating the presence of mandible invasion was 100%, and the accuracy of CBCT in evaluating the presence of nerve invasion was 69.2%. A mean deviation of 2.97 mm was found for assessment of the boundary of bone invasion using CBCT compared with the histopathological standard. The interexaminer agreement and intraexaminer agreement were perfect for the detection of bone invasion and nerve invasion (κ > 0.8). The intraclass correlation coefficient was 0.923 for the consistency test of boundary delineation on CBCT images. CONCLUSION: CBCT is quite reliable in determining the presence or absence of mandible invasion but not as reliable for nerve invasion. The deviation in bone invasion boundary estimation should be considered in osteotomy for OSCC.

Aged microplastics decrease the bioavailability of coexisting heavy metals to microalga Chlorella vulgaris.

Environmental aging of ubiquitous microplastics (MP) occurs through the action of biotic and abiotic factors, and aged MP exhibit different physicochemical properties and environmental behavior from virgin MP. This study aimed to investigate the aged micro-sized polystyrene (mPS) and polyvinyl chloride (mPVC), and the heavy metals copper (Cu) and cadmium (Cd), and examine the effects of their combined toxicities on microalga Chlorella vulgaris. Results showed that the presence of MP inhibited cell growth as compared with the control, the inhibition rate (I) decreased as concentrations of MP rose and aged MP exhibited stronger inhibition of cells than did virgin MP. The largest I was achieved in each culture with the MP concentration of 0.01 g/L, in which aged mPS with the maximal of 36.84% (Iaged mPS) followed by aged mPVC (Iaged mPVC = 30.03%), virgin mPS (Ivirgin mPS = 29.10%) and virgin mPVC (Ivirgin mPVC = 16.72%). Addition of the heavy metals Cu2+ and Cd2+ significantly inhibited cell growth, and toxicity increased with concentrations in a range of 0.5-2.0 mg/L; the maximum I values were 19.50% (ICu) and 85.14% (ICd), respectively. The combined toxicity of aged MP + Cu or aged MP + Cd was less than that of individual heavy metals. In particular, as compared with the maximal ICd of 85.14% achieved by single Cd2+, the toxicity of Cd2+ was greatly reduced when combined with aged mPS and mPVC, with the I value decreased to 27.55% (Iaged mPS) and 32.51% (Iaged mPVC), respectively. Both single and combined treatments caused cell damage to the microalga, accompanied by increased superoxide dismutase (SOD) and intracellular malonaldehyde (MDA) content.

l-cysteine-modified chiral gold nanoparticles promote periodontal tissue regeneration.

Gold nanoparticles (AuNPs) with surface-anchored molecules present tremendous potential in tissue regeneration. However, little is known about chiral-modified AuNPs. In this study, we successfully prepared L/D-cysteine-anchored AuNPs (L/D-Cys-AuNPs) and studied the effects of chiral-modified AuNPs on osteogenic differentiation and autophagy of human periodontal ligament cells (hPDLCs) and periodontal tissue regeneration. In vitro, more L-Cys-AuNPs than D-Cys-AuNPs tend to internalize in hPDLCs. L-Cys-AuNPs also significantly increased the expression of alkaline phosphatase, collagen type 1, osteocalcin, runt-related transcription factor 2, and microtubule-associated protein light chain 3 II and decreased the expression of sequestosome 1 in hPDLCs compared to the expression levels in the hPDLCs treated by D-Cys-AuNPs. In vivo tests in a rat periodontal-defect model showed that L-Cys-AuNPs had the greatest effect on periodontal-tissue regeneration. The activation of autophagy in L-Cys-AuNP-treated hPDLCs may be responsible for the cell differentiation and tissue regeneration. Therefore, compared to D-Cys-AuNPs, L-Cys-AuNPs show a better performance in cellular internalization, regulation of autophagy, cell osteogenic differentiation, and periodontal tissue regeneration. This demonstrates the immense potential of L-Cys-AuNPs for periodontal regeneration and provides a new insight into chirally modified bioactive nanomaterials.

Poor oral health conditions and cognitive decline: Studies in humans and rats.

BACKGROUND: The relationship between poor oral health conditions and cognitive decline is unclear. OBJECTIVE: To examine the association between oral health and cognition in humans and rats. METHODS: In humans: a cross-sectional study was conducted. Cognitive levels were evaluated by the Mini Mental State Examination (MMSE); oral conditions were reflected by the number of missing index teeth, bleeding on probing, and probing pocket depth (PD). In rats: a ligature-induced (Lig) periodontitis model and Aß25-35-induced model of Alzheimer's disease (AD) were established; tumor necrosis factor-α (TNF-α), interleukin 1 (IL-1), interleukin 6 (IL-6), and C-reactive protein levels in the hippocampus and cerebral cortex were detected. RESULTS: MMSE scores for the number of missing index teeth ≥ 7 group were significantly lower than those in the ≤ 6 group. A negative relationship (correlation coefficient ρ = -0.310, P = 0.002) was observed between MMSE scores and number of missing index teeth. More missing index teeth and lower education levels were independent risk factors for cognitive decline. A negative relationship (correlation coefficient ρ = -0.214, P = 0.031) was observed between MMSE scores and average PD. TNF-α and IL-6 levels in the hippocampus of the Lig+AD group were significantly higher than those of the AD group. IL-1 and IL-6 levels in the cerebral cortex of the Lig+AD group were significantly higher than those of the AD group. CONCLUSION: Poor oral health conditions including more missing index teeth and higher average PD may be risk factors for cognitive decline. Periodontitis may increase inflammatory cytokines in rat models of AD.

Occurrences and distribution of microplastic pollution and the control measures in China.

Microplastics (MPs) pollution has been increasingly investigated in marine and freshwater environments, even in atmosphere in China. Current literatures show that MPs contamination is highly related to human activities and geomorphology. Higher MPs occurrences were detected in freshwaters than those in seawaters in China. Furthermore, the abundance of MPs was influenced by many factors, including sampling method, unit of measurement, characteristics of sampling area, and others. Currently, investigating the condition of MPs occurrences and distribution on a broader scale and developing standardized protocol, along with basic toxicological research, will help to address crucial knowledge gaps regarding MPs pollution, their interaction with other pollutants and ecological consequences on individual, population or ecosystem levels in the environment. Meanwhile, this review calls for more efforts to be made for better and scientifically sound risk management for mitigation of MPs pollution in China.

Aged microplastics polyvinyl chloride interact with copper and cause oxidative stress towards microalgae Chlorella vulgaris.

Microplastics (MPs) could pose potential risks to microalgae, the primary producer of marine ecosystems. Currently, few studies focus on the interaction of aged MPs with other pollutants and their toxic effects to microalgae. Therefore, the present study aimed to investigate i) the aging of microplastics polyvinyl chloride (mPVC) in simulated seawater and the changes in physical and chemical properties; ii) the effects of single mPVC (virgin and aged) and copper on microalgae Chlorella vulgaris; and iii) the interaction of aged mPVC and copper and the oxidative stress towards C. vulgaris. In this study, some wrinkles, rough and fractured surface textures can be observed on the aged mPVC, accompanying with increased hydroxyl groups and aromatic carbon-carbon double bond but decreased carbon hydrogen bond. It was found that single virgin or aged mPVC at low concentration (10 mg/L) had significant inhibition on the growth of C. vulgaris but no inhibition at higher concentration (100, 1,000 mg/L), which can be reasonably explained by the aggregation and precipitation of mPVC at high concentration. The aging of mPVC inhibited the growth of C. vulgaris with the maximum growth inhibition ratio (IR) of 35.26% as compared with that of virgin mPVC (IR = 28.5%). However, the single copper could significantly inhibit the growth of C. vulgaris and the inhibitory effects increased with concentration (0.2, 0.5, 1.0 mg/L). Furthermore, both the single aged mPVC (10 mg/L) and copper (0.5 mg/L) caused serious cell damage, although the concentration of superoxide dismutase (SOD) and the intracellular malonaldehyde (MDA) increased. In contrast to single treatment, the growth of C. vulgaris can be enhanced by the combined group with copper (0.5 mg/L) and aged mPVC (10 mg/L).

Nitroxide radical-modified CuS nanoparticles for CT/MRI imaging-guided NIR-II laser responsive photothermal cancer therapy.

Herein, we reported nitroxide radical-modified CuS nanoparticles (CuS-NO˙ NPs), and they exhibited a typical absorption peak at 1182 nm. Due to such a long wavelength absorbance, CuS-NO˙ NPs exhibited excellent therapeutic outcome and low damage to normal tissues. Besides, we simultaneously achieved CuS-NO˙ NPs for MRI and CT dual-modal imaging, which successfully provided a new strategy for imaging-guided tumor treatment, thus increasing potential clinical applications for cancer treatment.

Development of an efficient genetic manipulation strategy for sequential gene disruption and expression of different heterologous GFP genes in Candida tropicalis.

The diploid yeast Candida tropicalis, which can utilize n-alkane as a carbon and energy source, is an attractive strain for both physiological studies and practical applications. However, it presents some characteristics, such as rare codon usage, difficulty in sequential gene disruption, and inefficiency in foreign gene expression, that hamper strain improvement through genetic engineering. In this work, we present a simple and effective method for sequential gene disruption in C. tropicalis based on the use of an auxotrophic mutant host defective in orotidine monophosphate decarboxylase (URA3). The disruption cassette, which consists of a functional yeast URA3 gene flanked by a 0.3 kb gene disruption auxiliary sequence (gda) direct repeat derived from downstream or upstream of the URA3 gene and of homologous arms of the target gene, was constructed and introduced into the yeast genome by integrative transformation. Stable integrants were isolated by selection for Ura+ and identified by PCR and sequencing. The important feature of this construct, which makes it very attractive, is that recombination between the flanking direct gda repeats occurs at a high frequency (10-8) during mitosis. After excision of the URA3 marker, only one copy of the gda sequence remains at the recombinant locus. Thus, the resulting ura3 strain can be used again to disrupt a second allelic gene in a similar manner. In addition to this effective sequential gene disruption method, a codon-optimized green fluorescent protein-encoding gene (GFP) was functionally expressed in C. tropicalis. Thus, we propose a simple and reliable method to improve C. tropicalis by genetic manipulation.