Ambient energy harvesters in wearable electronics: fundamentals, methodologies, and applications.

In recent years, wearable sensor devices with exceptional portability and the ability to continuously monitor physiological signals in real time have played increasingly prominent roles in the fields of disease diagnosis and health management. This transformation has been largely facilitated by materials science and micro/nano-processing technologies. However, as this technology continues to evolve, the demand for multifunctionality and flexibility in wearable devices has become increasingly urgent, thereby highlighting the problem of stable and sustainable miniaturized power supplies. Here, we comprehensively review the current mainstream energy technologies for powering wearable sensors, including batteries, supercapacitors, solar cells, biofuel cells, thermoelectric generators, radio frequency energy harvesters, and kinetic energy harvesters, as well as hybrid power systems that integrate multiple energy conversion modes. In addition, we consider the energy conversion mechanisms, fundamental characteristics, and typical application cases of these energy sources across various fields. In particular, we focus on the crucial roles of different materials, such as nanomaterials and nano-processing techniques, for enhancing the performance of devices. Finally, the challenges that affect power supplies for wearable electronic products and their future developmental trends are discussed in order to provide valuable references and insights for researchers in related fields.

Rapid segmentation and sensitive analysis of CRP with paper-based microfluidic device using machine learning.

Microfluidic paper-based analytical devices (µPADs) have been widely used in point-of-care testing owing to their simple operation, low volume of the sample required, and the lack of the need for an external force. To obtain accurate semi-quantitative or quantitative results, µPADs need to respond to the challenges posed by differences in reaction conditions. In this paper, multi-layer µPADs are fabricated by the imprinting method for the colorimetric detection of C-reactive protein (CRP). Different lighting conditions and shooting angles of scenes are simulated in image acquisition, and the detection-related performance of µPADs is improved by using a machine learning algorithm. The You Only Look Once (YOLO) model is used to identify the areas of reaction in µPADs. This model can observe an image only once to predict the objects present in it and their locations. The YOLO model trained in this study was able to identify all the reaction areas quickly without incurring any error. These reaction areas were categorized by classification algorithms to determine the risk level of CRP concentration. Multi-layer perceptron, convolutional neural network, and residual network algorithms were used for the classification tasks, where the latter yielded the highest accuracy of 96%. It has a promising application prospect in fast recognition and analysis of µPADs.

Highly thermal stable RNase A@PbS/ZnS quantum dots as NIR-IIb image contrast for visualizing temporal changes of microvasculature remodeling in flap.

Surgeons face great challenges in acquiring high-performance imaging because fluorescence probes with desired thermal stability remains rare. Here, hybrid lead sulfide/zinc sulfide quantum dots (PbS/ZnS QDs) nanostructures emitting in the long-wavelength end of the second near-infrared (NIR-IIb) window were synthesized and conjugated with Ribonuclease-A (RNase A). Such formed RNase A@PbS/ZnS QDs exhibited strong NIR IIb fluorescence and thermal stability, as supported by the photoluminescent emission assessment at different temperatures. This will allow the RNase A@PbS/ZnS QDs to provide stable fluorescence signals for long-time intraoperative imaging navigation, despite often happened, undesirable thermal accumulation in vivo. Compared to NIR-IIa fluorescence imaging, NIR-IIb vascular fluorescence imaging achieved larger penetration depth, higher signal/background ratios and nearly zero endogenous tissue autofluorescence. Moreover, these QDs illustrate the reliability during the real-time and long-time precise assessment of flap perfusion by clearly visualizing microvasculature map. These findings contribute to intraoperative imaging navigation with higher precision and lower risk.

Point-of-care biochemical assays using electrochemical technologies: approaches, applications, and opportunities.

Against the backdrop of hidden symptoms of diseases and limited medical resources of their investigation, in vitro diagnosis has become a popular mode of real-time healthcare monitoring. Electrochemical biosensors have considerable potential for use in wearable products since they can consistently monitor the physiological information of the patient. This review classifies and briefly compares commonly available electrochemical biosensors and the techniques of detection used. Following this, the authors focus on recent studies and applications of various types of sensors based on a variety of methods to detect common compounds and cancer biomarkers in humans. The primary gaps in research are discussed and strategies for improvement are proposed along the dimensions of hardware and software. The work here provides new guidelines for advanced research on and a wider scope of applications of electrochemical biosensors to in vitro diagnosis.

An Innovative and Economical Device for Ischemic Preconditioning of the Forehead Flap Prior to Pedicle Division: A Comparative Study.

BACKGROUND: Ischemic preconditioning of the forehead flap prior to pedicle division helps to improve angiogenesis. Clamping the pedicle by a clamped rubber band with vessel forceps is often clinically applied. However, the severe pain and unstable blocking effect influenced the preconditioning process. In this study, we described an innovative device designed for ischemic preconditioning and compared its efficacy with the clamped rubber band. METHODS: The device consists of a self-locking nylon cable tie with a buckle and a rubber tube. The rubber tube is fed over the cable tie to act as a soft outer lining and the cable tie is tightened across the pedicle to block the perfusion for ischemic preconditioning. This device and the standard clamped rubber band were applied respectively before division surgery. The constriction effect, reliability, reproducibility, and the patients' pain tolerance were compared. RESULTS: A total of 20 forehead flaps were included. The cable tie had less incidence of loosening (7.7% vs. 16.6%, p < 0.05) and maintained the pressure more effectively. The pain score for the nylon cable tie was significantly lower than the clamped rubber band (4.25 ± 1.02 vs. 6.75 ± 1.12, p < 0.05), especially for 10 pediatric patients (4.50 ± 0.85 vs. 8.10 ± 1.20, p < 0.01). All 20 pedicles were successfully divided at 19 to 22 days with no surgical complications. CONCLUSION: Compared with the clamped rubber band, the cable tie produces a more reliable and reproducible ischemic preconditioning effect. It is also better tolerated by the patients. Therefore, we recommend using the nylon cable tie as the preferred device for ischemic preconditioning of the forehead flap.

3D Mesh Releasing Method: A Retrospective Analysis of Fractional CO2 Treatment on Contracture Scars.

BACKGROUND AND OBJECTIVES: There has been reports on fractional CO2 laser successfully improving contracture scars that impair the function of a joint. It seems that certain contracture problems could be solved by laser instead of surgery. However, the clinical application could be difficult when the efficacy of the method remains unknown. The purpose of this study is to report the releasing capacity of the fractional CO2 laser on contracture scars based on a defined treatment method. STUDY DESIGN/MATERIALS AND METHODS: We conducted a retrospective study in patients with limited function in joints caused by contracture scars. Fractional CO2 laser and our "3D mesh releasing" protocol were applied. The primary outcome was the improvement measured in range of motion (ROM) of the relevant joint before all intervention and 6 months after the last treatment. RESULT: From November 2016 to January 2018, 11 joints of 10 cases were treated by the fractional CO2 laser. Patients went through 2.27 (standard deviation [SD] 1.42, 1-5) sessions. The average progress of ROM before and 6 months after all treatments was 19.13° (SD 10.25, P < 0.02). In six cases, we recorded that there was an 8.53° (SD 5.81, P < 0.02) of increase in ROM immediately after the laser session, and the average improvement reached up to 13.58° (SD 8.15, P < 0.02) after 2-3 months during the next follow-up. CONCLUSION: The fractional CO2 laser could achieve functional improvement in contracture scars and it maintained its effect for at least 6 months. The "3D Mesh Releasing" protocol would help to standardize the treatment procedure. This modality has minimal-invasiveness and potentially could become a supplement to the current treatment choices for mild contracture scars. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

A Prospective Comparative Study of Color Doppler Ultrasound and Infrared Thermography in the Detection of Perforators for Anterolateral Thigh Flaps.

BACKGROUND: Preoperative localization of the perforators allows precise planning of the flap design and improves surgical efficiency. Recently, infrared thermography is introduced as a reliable alternative, where the perforator corresponds to the "hot spot" on the thermogram. This study aims to compare the application of color Doppler ultrasound (CDU) and infrared thermography in preoperative perforator mapping of the anterolateral thigh (ALT) perforator flap. PATIENTS AND METHODS: From September 2017 to January 2019, CDU and infrared thermography were both applied on 20 patients to locate the perforators originated from lateral circumflex femoral artery preoperatively. The perforators identified using each modality were marked on the anterolateral thigh region. The accuracy of both mapping methods was analyzed according to the intraoperative findings. The relation between location bias and the thickness of subcutaneous tissue was analyzed. RESULTS: A total of 20 ALT flaps were included. Fifty-three perforators were detected by CDU, and 51 "hot spots" were identified by infrared thermography, in which 50 "hot spots" corresponded to CDU, and the consistency test showed that the κ index was 0.712 (P < 0.05), representing high consistency. The infrared thermography has a sensitivity of 94.3% and a specificity of 85.7% compared with CDU. The deviation between thermal imaging and CDU was positively correlated with the thickness of the subcutaneous tissue. The Pearson correlation coefficient was 0.84 (R = 0.84). Forty-four perforators marked by CDU were selected for designing the flap. Anatomical findings showed that the accuracy rate of CDU and infrared thermal was 93.2% (41 of 44) and 86.3% (38 of 44), respectively. There was no statistical difference (P > 0.05). CONCLUSIONS: Compared with CDU, infrared thermography can be used to locate perforators, in this case, the ALT perforators, with a high degree of consistency. It is portable, economical, noninvasive, and easy to operate. It has higher accuracy in patients with thinner subcutaneous tissue. We believe that infrared thermography can be a useful technique for perforator mapping, especially in patients where the subcutaneous tissue is thinner.

The Injection for the Lower Eyelid Retraction: A Mechanical Analysis of the Lifting Effect of the Hyaluronic Acid.

BACKGROUND: It has been reported that the injection of the hyaluronic acid (HA) into the lower lid area could improve lower eyelid retraction. However, the published studies offered few insights into the mechanism of this treatment. When the underlying mechanism is not clear, many surgeons will not trust the method enough to apply it in their clinical practice. The purpose of this article was to propose a possible explanation for the underlying mechanism of the treatment and further verify the method by a series of cases. METHODS: The authors performed a mechanical analysis on the physical impact of HA on the lower eyelid. In the clinical cases, we injected the fillers under the orbicularis muscle to correct lower lid retraction. The results were evaluated by the standardized marginal reflex distance 2 (MRD2) immediately and 9 months later. RESULTS: From October 2013 to October 2015, the injections were carried out in 27 cases (14 post-blepharoplasty and 13 involuntary). In 26 cases (96.3%), the retraction was completely corrected and did not recur through the last follow-up. The average improvement of the standardized MRD2 was 0.84 mm immediately after the injection and 1.19 mm 9 months later. Complications were not reported. CONCLUSION: Lower eyelid retraction could be treated by the injection of HA under the orbicularis muscle. The filler in this situation acted as a lifter because the filler changed the balance of force of the lower lid, forcing it to shift upward to gain the new balance. The 'lifter' mechanism could be applicable to other facial injections that generate elevating effects. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Application of Indocyanine Green in Flap Surgery: A Systematic Review.

BACKGROUND: The vascularization of the distal portions of transferred tissue represents the most critical factor in the success of reconstructive surgery. In recent years, indocyanine green (ICG) fluorescence imaging techniques have been applied during surgery to evaluate flap perfusion. However, this investigation has found that there is little consensus regarding the standard dose of ICG as well as the pre-operative requirements of ICG allergy testing. The aim of this study is to summarize the applications of ICG to tissue transfers and safe dosing practices and to provide insight to the possible adverse effects of ICG on flap surgery with the goal of helping clinicians apply ICG safely and efficiently to tissue transfer procedures. METHODS: A literature search was performed using, Wiley InterScience, and Springer with the key words, 'Flap,' 'indocyanine green,' 'surgery,' and related mesh words for all publications between 2005 and 2015. Title and abstract screening was performed using predefined in- and exclusion criteria. RESULTS: Seventy-three articles were included. These were classified as "application of ICG in flap surgery" and "the security of applying ICG in flap surgery". CONCLUSIONS: ICG fluorescence imaging preoperatively facilitates the detection of perforators in tissue flaps with thickness <20 mm, aids in the evaluation of flap microcirculation and perfusion, and allows surgeons to select dominant cutaneous nerves while evaluating the quality of vascular anastomoses and locating thromboses. The literature also concluded that potential allergic reactions to ICG should be taken into consideration.

Modified S-Flap for Nipple Reconstruction.

BACKGROUND: Nipple reconstruction is an important last step in the process of autologous or implant-based breast reconstruction. A multitude of techniques have been described, among others the S-flap. To prevent nipple retraction after surgery, we modified the originally described method by Cronin. METHODS: By adding an S-shaped incision line, the flap can be transposed with less tension and sutured on top of the new nipple along a curved line. Furthermore, two small triangular flaps were inserted at the base for reinforcement and reduced linear contraction. Assessment was completed by measuring nipple diameter and projection with a caliper. RESULTS: A total of 16 patients underwent the technique, of whom 11 could be followed after 3 and 6 months. Overall patient satisfaction with the aesthetic result was high, and we observed no infection or necrosis. Nipples were stable in size and shape at 6 months. Although reduction of 68% in projection and 31% in diameter was observed, the nipples remained pleasantly similar to the contralateral non-operated side. CONCLUSIONS: The modified S-flap is a simple and reliable technique for moderate-sized nipple reconstruction. By providing more tissue at the base, size and projection remain stable and durable. Moreover, by a modified linear incision line at the base, tension and subsequent scar contraction is minimal. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Prefabricated Flaps: Identification of Microcirculation Structure and Supercharging Technique Improving Survival Area.

Background Microcirculation is an important factor frequently overlooked when studying the survival of prefabricated flaps. In the current study, we use different prefabrication techniques for characterizing microcirculation within the flap, with the goal of finding an effective way to improve its survival area. Methods An abdominal prefabricated flap rodent model was created using a two-stage operation. All rats were randomly divided into six groups (n = 10/group): group A, prefabricated femoral vessels; group B, prefabricated femoral artery with a connected superficial inferior epigastric vein (SIEV); group C, connected superficial inferior epigastric artery (SIEA) with a prefabricated femoral vein; group D was similar to group A along with a prefabricated SIEA, and group E was similar to group A along with a prefabricated SIEV; and group F acted as a control group and consisted of an axial flap nourished by superficial inferior epigastric vessels. Flaps were assessed for survival area, blood perfusion area, and capillary density using macroscopic analysis, near-infrared fluorescence imaging (NIFI), and histology. Results The survival area was not significantly different when comparing groups B to C, and D to E. The survival area of groups D and E was larger than that of groups B and C. Groups B through E had a smaller survival area in comparison to group F and a larger survival area than group A. NIFI were consistent with the macroscopic outcomes. The capillary density was not significantly different between groups A to C and groups D to F. Conclusion Both arterial and venous supercharging could potentially improve the survival area of prefabricated flaps.

Sebum Production Alteration after Botulinum Toxin Type A Injections for the Treatment of Forehead Rhytides: A Prospective Randomized Double-Blind Dose-Comparative Clinical Investigation.

BACKGROUND: Research has investigated the decrease in human skin sebum after the application of botulinum toxin. Few studies of the mechanism and objective assessments of this phenomenon have been conducted and the correlation between the sebum production and injection dosages or techniques remains unclear. OBJECTIVES: We prospectively investigated the sebum regulation and its gradient around the injection site in patients who received intramuscular injections of botulinum toxin A (BTX-A) for forehead rhytides, comparing two injection doses. METHODS: Forty-two female volunteers with rhytides on the forehead region were randomly assigned to receive 10 or 20 units of BTX-A, which was administered in five standard injection sites. The baseline and post-treatment sebum production was measured using a Sebumeter. RESULTS: Treatment with BTX-A exhibited significant sebum alteration at the injection site of both groups, with a sebum gradient surrounding the injection point. The efficacy did not improve at higher injection doses, with the four-unit regimen generally not being more potent than the two-unit regimen. The sebum production recovered to normal levels at the 16 week follow-up for both treatment groups, indicating that a higher dosage (four units) did not result in a longer duration until relapse compared with the two-unit dose. CONCLUSIONS: We determined that the sebum production has a positive correlation with the distance away from the injection point. Intramuscular injection of BTX-A significantly reduces sebum production at the injection site but increases the sebum production of the surrounding skin at a radius of 2.5 cm at the 2, 4, and 8 week follow-ups. LEVEL OF EVIDENCE: 2 Therapeutic.

A prospective study of medial sural artery perforator flap with computed tomographic angiography-aided design in tongue reconstruction.

PURPOSE: To investigate the application of the medial sural artery perforator flap in hemiglossectomy reconstruction and evaluate the value of preoperative computed tomographic angiography (CTA) for perforator location. PATIENTS AND METHODS: Nine patients received medial sural artery perforator flaps for tongue reconstruction from August 2013 to January 2014. Of the 9 patients, 5 were male and 4 were female, with a mean age of 51 years (range 22 to 67). The number, location, and course of the perforators were measured on the CTA preoperatively. RESULTS: Of the 9 medial sural artery perforator flaps, 8 survived and 1 had developed necrosis. Thirteen perforators had been visualized by CTA, and 10 of these were used in the operation. No significant difference was found between the CTA location and the intraoperative findings in the perforators' distribution. The mean diameter of the medial sural artery was 1.0 ± 0.3 mm and of the concomitant vein was 2.0 ± 0.7 mm. The mean pedicle length was 9.7 ± 1.0 cm, with 5.1 ± 1.7 cm of the main trunk and 4.6 ± 2.1 cm of the perforator. The average number of muscular vessel branches was 23.9 ± 6.9, with 12.2 ± 5.1 from the main trunk and 10.1 ± 4.4 from the perforators; 1 (10%) perforator was septocutaneous and 9 (90%) were myocutaneous. CONCLUSIONS: The medial sural artery perforator flap is appropriate for medium-size tongue defect reconstruction, with a long pedicle of matching caliber, adequate tissue volume, and minimal donor site morbidity. CTA is a valuable and necessary method for preoperative assessment of the perforator's location.

Objective breast volume, shape and surface area assessment: a systematic review of breast measurement methods.

BACKGROUND: There are many methods of measuring the breast and their clinical applications are well described in the literature. However, there has been no attempt to compare these various methods to allow the user to have a broad overview of the subject. The authors have attempted to summarise all the available methods to measure the breast in this article to provide a useful reference for all. METHODS: A comprehensive literature search of PubMed was performed, and the resulting articles were screened and reviewed. The data regarding the methods' mechanism, reliability, time and cost were evaluated and compared. RESULTS: A total of 74 articles dating from 1970 to 2013 were included in this study. All of the methods can be classified into those that measure (1) volume, (2) shape and (3) surface area. Each category consists of several methods that work through different mechanisms and they vary in their reliability and feasibility. Based on their mechanism, the volume measurement methods were further grouped into the natural shape methods, the stereological method, the geometrical methods and the mathematical modelling method. CONCLUSIONS: More objective breast evaluation can be achieved if all three dimensions (volume, shape and surface area) are considered. In the volume measurements, 3D modelling and the MRI are the most reliable tools. Linear measurement (geometry) and mathematical modelling are less accurate but are more economical. In the shape measurements, besides the traditional linear measurement, 3D methods that can deliver colour-coded maps and Swanson's 2D photographic measurement system are capable of depicting and tracking breast shape changes after surgery. Although the surface area metric has not been used extensively, it has potential in clinical and research applications. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Immunochromatographic enhancement strategy for SARS-CoV-2 detection based on nanotechnology.

The global outbreak of coronavirus disease 2019 (COVID-19) has been catastrophic to both human health and social development. Therefore, developing highly reliable and sensitive point-of-care testing (POCT) for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a priority. Among all available POCTs, the lateral flow immunoassay (LFIA, also known as immunochromatography) has proved to be effective due to its accuracy, portability, convenience, and speed. In areas with a scarcity of laboratory resources and medical personnel, the LFIA provides an affordable option for the diagnosis of COVID-19. This review offers a comprehensive overview of methods for improving the sensitivity of SARS-CoV-2 detection using immunochromatography based on nanotechnology, sorted according to the different detection targets (antigens, antibodies, and nucleic acids). It also looks into the performance and properties of the various sensitivity enhancement strategies, before delving into the remaining challenges in COVID-19 diagnosis through LFIA. Ultimately, it seeks to provide helpful guidance in selecting an appropriate strategy for SARS-CoV-2 immunochromatographic detection based on nanotechnology.

Dual-signal readout paper-based wearable biosensor with a 3D origami structure for multiplexed analyte detection in sweat.

In this research, we design and implement a small, convenient, and noninvasive paper-based microfluidic sweat sensor that can simultaneously detect multiple key biomarkers in human sweat. The origami structure of the chip includes colorimetric and electrochemical sensing regions. Different colorimetric sensing regions are modified with specific chromogenic reagents to selectively identify glucose, lactate, uric acid, and magnesium ions in sweat, as well as the pH value. The regions of electrochemical sensing detect cortisol in sweat by molecular imprinting. The entire chip is composed of hydrophilically and hydrophobically treated filter paper, and 3D microfluidic channels are constructed by using folding paper. The thread-based channels formed after the hydrophilic and hydrophobic modifications are used to control the rate of sweat flow, which in turn can be used to control the sequence of reactions in the differently developing colored regions to ensure that signals of the best color can be captured simultaneously by the colorimetric sensing regions. Finally, the results of on-body experiments verify the reliability of the proposed sweat sensor and its potential for the noninvasive identification of a variety of sweat biomarkers.

Vascularized lymph node flaps can survive on venous blood without an arterial inflow: an experimental model describing the dynamics of venous flow using indocyanine green angiography (With video).

Background: Several surgeons have described studies of free-tissue transfers using veins instead of arteries. These innovative microsurgical techniques can offer several advantages, such as an easier dissection during flap harvesting, and represent an alternative during an accidental surgical mistake or development of new surgical procedures. The purpose of this study was to describe and explore different constructs of vascularized lymph node transfer (VLNT) only based on venous blood flow in a mouse model, evaluate their blood flow microcirculation through indocyanine green (ICG) angiography and investigate the lymphatic drainage function and the lymph nodes' structures. Methods: Five types of venous lymph node flaps (LNF) were created and investigated: Types IA, IB, IC, IIA and IIB were developed by ICG intraoperatively (with videos in the article). Seven weeks later, by applying methylene blue, the recanalization of the lymphatic vessels between the LNF and the recipient site was detected. Lymph nodes were collected at the same time and their structures were analyzed by hematoxylin and eosin staining analysis. Results: All of the venous LNFs developed except Type IC. Seven weeks later, methylene blue flowed into Types IA, IB, IIA and IIB from recipient sites. When comparing with arteriovenous lymph node, the medullary sinus was diffusely distributed in venous lymph nodes. The proportion of cells was significantly reduced (p < 0.05). The artery diameters were significantly smaller (p < 0.05). The veins diameters and lymphatic vessels output in Types IA, IB, IIA and IIB were more dilated (p < 0.05). Conclusions: This research demonstrated that Type IA, IB, IIA and IIB venous LNFs can retrogradely receive venous blood supply; they can survive, produce a lymphatic recanalization and integrate with the surrounding tissue, despite lymph node structural changes. Our results will improve the understanding of the survival mechanism of venous LNFs and will help researchers to design new studies or lymphatic models and eventually find an alternative procedure for the surgical treatment of lymphedema.

In Vivo Precision Evaluation of Lymphatic Function by SWIR Luminescence Imaging with PbS Quantum Dots.

Advancements in lymphography technology are essential for comprehensive investigation of the lymphatic system and its function. Here, a shortwave infrared (SWIR) luminescence imaging of lymphatic vessels is proposed in both normal and lymphatic dysfunction in rat models with PbS quantum dots (PbS Qdots). The lymphography with PbS Qdots can clearly and rapidly demonstrate the normal lymphatic morphology in both the tail and hind limb. More importantly, compared to ICG, SWIR luminescence imaging with PbS Qdots can easily identify the dominant lymphatic vessel and node with higher luminescence signal in rats. Moreover, lymphatic pump is identified as segment contracting sections with a size of ≈1 cm in rat by in vivo SWIR lymphograhy, which propose a direct feature for precise evaluation of lymphatic function. Notably, in vivo SWIR luminescence imaging with PbS Qdots also clearly deciphers the in vivo pattern of morphological and function recovery from lymphatic system in rat model. In summary, SWIR luminescence imaging with PbS Qdots can improve the lymphography and thus deepen the understanding of the morphology and structure of the lymphatic system as well as lymphatic function such as lymphatic pump, which will facilitate the diagnosis of lymphatic dysfunction in the future.

NIR-II live imaging study on the degradation pattern of collagen in the mouse model.

The degradation of collagen in different body parts is a critical point for designing collagen-based biomedical products. Here, three kinds of collagens labeled by second near-infrared (NIR-II) quantum dots (QDs), including collagen with low crosslinking degree (LC), middle crosslinking degree (MC) and high crosslinking degree (HC), were injected into the subcutaneous tissue, muscle and joints of the mouse model, respectively, in order to investigate the in vivo degradation pattern of collagen by NIR-II live imaging. The results of NIR-II imaging indicated that all tested collagens could be fully degraded after 35 days in the subcutaneous tissue, muscle and joints of the mouse model. However, the average degradation rate of subcutaneous tissue (k = 0.13) and muscle (k = 0.23) was slower than that of the joints (shoulder: k = 0.42, knee: k = 0.55). Specifically, the degradation rate of HC (k = 0.13) was slower than LC (k = 0.30) in muscle, while HC showed the fastest degradation rate in the shoulder and knee joints. In summary, NIR-II imaging could precisely identify the in vivo degradation rate of collagen. Moreover, the degradation rate of collagen was more closely related to the implanted body parts rather than the crosslinking degree of collagen, which was slower in the subcutaneous tissue and muscle compared to the joints in the mouse model.

Mercury chloride activates the IFNγ-IRF1 signaling in myeloid progenitors and promotes monopoiesis in mice.

Inorganic mercury (Hg2+) is a highly toxic heavy metal in the environment. To date, the impacts of Hg2+ on the development of monocytes, or monopoiesis, have not been fully addressed. The aim of the present study was to investigate the impact of Hg2+ on monopoiesis. In this study, we treated B10.S mice and DBA/2 mice with 10 µM or 50 µM HgCl2 via drinking water for 4 wk, and we then evaluated the development of monocytes. Treatment with 50 µM HgCl2, but not 10 µM HgCl2, increased the number of monocytes in the blood, spleen and bone marrow (BM) of B10.S mice. Accordingly, treatment with 50 µM HgCl2, but not 10 µM HgCl2, increased the number of common myeloid progenitors (CMP) and granulocyte-macrophage progenitors (GMP) in the BM. Functional analyses indicated that treatment with 50 µM HgCl2 promoted the differentiation of CMP and GMP to monocytes in the BM of B10.S mice. Mechanistically, treatment with 50 µM HgCl2 induced the production of IFNγ, which activated the Jak1/3-STAT1/3-IRF1 signaling in CMP and GMP and enhanced their differentiation potential for monocytes in the BM, thus likely leading to increased number of mature monocytes in B10.S mice. Moreover, the increased monopoiesis by Hg2+ was associated with the increased inflammatory status in B10.S mice. In contrast, treatment with 50 µM HgCl2 did not impact the monopoiesis in DBA/2 mice. Our study reveals the impact of Hg on the development of monocytes.