Photothermal-Controllable Microneedles with Antitumor, Antioxidant, Angiogenic, and Chondrogenic Activities to Sequential Eliminate Tracheal Neoplasm and Reconstruct Tracheal Cartilage

The optimal treatment for tracheal tumors necessitates sequential tumor elimination and tracheal cartilage reconstruction. This study introduces an innovative inorganic nanosheet, MnO2 /PDA@Cu, comprising manganese dioxide (MnO2 ) loaded with copper ions (Cu) through in situ polymerization using polydopamine (PDA) as an intermediary. Additionally, a specialized methacrylic anhydride modified decellularized cartilage matrix (MDC) hydrogel with chondrogenic effects is developed by modifying a decellularized cartilage matrix with methacrylic anhydride. The MnO2 /PDA@Cu nanosheet is encapsulated within MDC-derived microneedles, creating a photothermal-controllable MnO2 /PDA@Cu-MDC microneedle. Effectiveness evaluation involved deep insertion of the MnO2 /PDA@Cu-MDC microneedle into tracheal orthotopic tumor in a murine model. Under 808 nm near-infrared irradiation, facilitated by PDA, the microneedle exhibited rapid overheating, efficiently eliminating tumors. PDA's photothermal effects triggered controlled MnO2 and Cu release. The MnO2 nanosheet acted as a potent inorganic nanoenzyme, scavenging reactive oxygen species for an antioxidant effect, while Cu facilitated angiogenesis. This intervention enhanced blood supply at the tumor excision site, promoting stem cell enrichment and nutrient provision. The MDC hydrogel played a pivotal role in creating a chondrogenic niche, fostering stem cells to secrete cartilaginous matrix. In conclusion, the MnO2 /PDA@Cu-MDC microneedle is a versatile platform with photothermal control, sequentially combining antitumor, antioxidant, pro-angiogenic, and chondrogenic activities to orchestrate precise tracheal tumor eradication and cartilage regeneration.

Does Dual Anti-HER2 Therapy Increase Early Cardiac Toxicity in Comparison with Trastuzumab Alone in Breast Cancer Patients Receiving Adjuvant Radiotherapy? A Multicenter Retrospective Study

PURPOSE/OBJECTIVE(S)

Adjuvant trastuzumab in combination with RT has proved its safety in terms of cardiac events. Dual anti-HER2 therapy with pertuzumab is currently standard adjuvant therapy in N+ and high-risk N0 early breast cancer (BC) patients. Our study aims to find if it increases early cardiac toxicity compared with trastuzumab alone in BC patients receiving adjuvant radiotherapy.

MATERIALS/METHODS

Operable BC patients who received adjuvant radiotherapy (RT) and trastuzumab with or without pertuzumab between January 2017 and September 2020 in 7 Chinese centers were retrospectively reviewed. The cardiac examination included ultrasonography, electrocardiogram (ECG), NT-proBNP, and cTnI before RT and during follow-up. The cardiac event was any new-onset symptomatic heart disease or abnormality in the cardiac examination after RT.

RESULTS

In total, 711 patients with a median age of 52 years were included, of whom 567 (79.7%) patients were treated with trastuzumab-only and 144 (20.3%) patients received dual anti-HER2 therapy. Adjuvant RT was given concurrently in 140/144 (97.2%) of dual anti-HER2 therapy and 562/567 (99.1%) of trastuzumab alone, respectively. With a median follow-up of 11 months, no patients developed symptomatic heart diseases. Among patients with normal baseline, 17 (2.4%), 86 (12.1%), 18 (2.5%) and 14 (7.3%) developed new-onset diastolic dysfunction, left ventricular ejection fraction (LVEF) decline, abnormal ECG, and abnormal NT-proBNP, respectively. No significant difference was found between the trastuzumab-only and dual anti-HER2 cohort in the incidence of all kinds of new-onset cardiac events (all p > 0.1). Multivariate analysis showed that left-sided (vs right-sided) RT significantly increased the risk of ECG abnormality (HR = 2.32, 95% CI 1.62-3.32, p<0.001). Increased age was an independent risk factor for diastolic dysfunction (HR = 1.1, 95% CI 1.02-1.18, p = 0.0098). Dosimetric analysis showed that patients who developed any cardiac events had increased mean heart dose (397.67±251.08 vs 344.87±236.75 cGy, p = 0.032). A significant increase in risk of cardiac events was found in patients with mean heart dose > 450 cGy (HR = 1.55, 95% CI 1.17-2.05, p = 0.0024), V5 > 26% (HR = 1.51, 95% CI 1.09-2.09, p = 0.013), and V30 > 5.5% (HR = 1.49, 95% CI 1.09-2.04, p = 0.0117), respectively. Further analysis was done in the subgroup of patients treated with left-sided RT, internal mammary nodes RT, or anthracyclines, no difference in risk of cardiac events was found between trastuzumab alone and dual anti-HER2 therapy in concurrent with RT (all p > 0.05).

CONCLUSION

Compared with trastuzumab-only, dual anti-HER2 therapy does not increase early cardiac toxicity in combination with adjuvant RT in BC patients. Cardiac radiation exposure remains the primary risk factor associated with early cardiac toxicity.

[Artificial intelligence-assisted identification of mucus plugs in asthma]

Airway mucus plug is an important clinical feature of bronchial asthma and is related to the prognosis of the disease. Clinically, chest CT is a preferred tool for evaluating airway mucus plugs. At present, the interpretation of CT images relies on manual reading, but the airway mucus plugs of patients with bronchial asthma are mostly distributed in the small and medium airways, which are difficult to identify with the naked eye. In recent years, with the continuous progress of deep learning and big data technology, artificial intelligence (AI)-assisted image reading technology has been introduced into clinical application, which has significantly improved the efficiency and accuracy of mucus plug identification. Currently, AI-assisted airway mucus plug identification has been used in respiratory diseases such as cystic fibrosis, chronic obstructive pulmonary disease, and bronchial asthma. Therefore, the application of AI counting to mucus plugs in patients with bronchial asthma is of great significance.

Cerebrospinal fluid can exit into the skull bone marrow and instruct cranial hematopoiesis in mice with bacterial meningitis

Interactions between the immune and central nervous systems strongly influence brain health. Although the blood-brain barrier restricts this crosstalk, we now know that meningeal gateways through brain border tissues facilitate intersystem communication. Cerebrospinal fluid (CSF), which interfaces with the glymphatic system and thereby drains the brain's interstitial and perivascular spaces, facilitates outward signaling beyond the blood-brain barrier. In the present study, we report that CSF can exit into the skull bone marrow. Fluorescent tracers injected into the cisterna magna of mice migrate along perivascular spaces of dural blood vessels and then travel through hundreds of sub-millimeter skull channels into the calvarial marrow. During meningitis, bacteria hijack this route to invade the skull's hematopoietic niches and initiate cranial hematopoiesis ahead of remote tibial sites. As skull channels also directly provide leukocytes to meninges, the privileged sampling of brain-derived danger signals in CSF by regional marrow may have broad implications for inflammatory neurological disorders.

Quantification of bone marrow interstitial pH and calcium concentration by intravital ratiometric imaging

The fate of hematopoietic stem cells (HSCs) can be directed by microenvironmental factors including extracellular calcium ion concentration ([Ca2+]e), but the local [Ca2+]e around individual HSCs in vivo remains unknown. Here we develop intravital ratiometric analyses to quantify the absolute pH and [Ca2+]e in the mouse calvarial bone marrow, taking into account the pH sensitivity of the calcium probe and the wavelength-dependent optical loss through bone. Unexpectedly, the mean [Ca2+]e in the bone marrow (1.0 ± 0.54 mM) is not significantly different from the blood serum, but the HSCs are found in locations with elevated local [Ca2+]e (1.5 ± 0.57 mM). With aging, a significant increase in [Ca2+]e is found in M-type cavities that exclusively support clonal expansion of activated HSCs. This work thus establishes a tool to investigate [Ca2+]e and pH in the HSC niche with high spatial resolution and can be broadly applied to other tissue types.

Intravital fluorescence microscopy with negative contrast

Advances in intravital microscopy (IVM) have enabled the studies of cellular organization and dynamics in the native microenvironment of intact organisms with minimal perturbation. The abilities to track specific cell populations and monitor their interactions have opened up new horizons for visualizing cell biology in vivo, yet the success of standard fluorescence cell labeling approaches for IVM comes with a "dark side" in that unlabeled cells are invisible, leaving labeled cells or structures to appear isolated in space, devoid of their surroundings and lacking proper biological context. Here we describe a novel method for "filling in the void" by harnessing the ubiquity of extracellular (interstitial) fluid and its ease of fluorescence labelling by commonly used vascular and lymphatic tracers. We show that during routine labeling of the vasculature and lymphatics for IVM, commonly used fluorescent tracers readily perfuse the interstitial spaces of the bone marrow (BM) and the lymph node (LN), outlining the unlabeled cells and forming negative contrast images that complement standard (positive) cell labeling approaches. The method is simple yet powerful, offering a comprehensive view of the cellular landscape such as cell density and spatial distribution, as well as dynamic processes such as cell motility and transmigration across the vascular endothelium. The extracellular localization of the dye and the interstitial flow provide favorable conditions for prolonged Intravital time lapse imaging with minimal toxicity and photobleaching.

Nonlinear microfluidics: device physics, functions, and applications

The microfluidic flow is typically laminar due to the dominant viscous effects. At Reynolds numbers far below 1 (Re ≪ 1), the fluid inertia can be neglected. For the steady flow of incompressible Newtonian fluids, it approaches linear Stokes flow. At intermediate Re, there exists a weak-inertia flow regime where secondary flows such as Dean vortices are accessible for microfluidic manipulations. Apart from the fluid inertia, other nonlinear factors such as the non-Newtonian fluid properties, concurrent flow of dissimilar fluids, compliant fluidic structures and stimuli-responsive materials can also cause intriguing flow behaviours. Through proper designs, they can be applied for a variety of microfluidic components including mixers, valves, oscillators, stabilizers and auto-regulators etc., greatly enriching the microfluidic flow control and manipulation strategies. Due to its unique working characteristics and advantages, nonlinear microfluidics has increasingly attracted extensive attention. This review presents a systematic survey on this subject. The designs of typical nonlinear microfluidic devices, their working mechanisms, key applications, and the perspective of their future developments will be discussed. The nonlinear microfluidic techniques are believed to play an essential role in the next generation of highly-integrated, automated, and intelligent microfluidics.

Enhancement of cadmium accumulation in sweet sorghum as affected by nitrate

The Cadmium (Cd)-polluted soils are is an increasing concern worldwide. Phytoextraction of Cd pollutants by high biomass plants, such as sweet sorghum, is considered an environmentally-friendly, cost-effective and sustainable strategy for remediating this problem. Nitrogen (N) is a macronutrient essential for plant growth, development and stress resistance. Nevertheless, how nitrate, as an important form of N, affects Cd uptake, translocation and accumulation in sweet sorghum is still unclear. In the present study, a series of nitrate levels (N1, 0.5 mm; N2, 2 mm; N3, 4 mm; N4, 8 mm and N5, 16 mm) with or without added 5 μm CdCl₂ treatment in sweet sorghum was investigated hydroponically. The results indicate that Cd accumulation in the aboveground parts of sweet sorghum was enhanced by optimum nitrate supply, resulting from both increased dry weight and Cd concentration. Although root-to-shoot Cd translocation was not enhanced by increased nitrate, some Cd was transferred from cell walls to vacuoles in leaves. Intriguingly, expression levels of Cd uptake and transport genes, SbNramp1, SbNramp5 and SbHMA3, were not closely related to increased Cd as affected by nitrate supply. The expression of SbNRT1.1B in relation to nitrate transport showed an inverted 'U' shape with increasing nitrate levels under Cd stress, which was in agreement with trends in Cd concentration changes in aboveground tissues. Based on the aforementioned results, nitrate might regulate Cd uptake and accumulation through expression of SbNRT1.1B rather than SbNramp1, SbNramp5 or SbHMA3, the well-documented genes related to Cd uptake and transport in sweet sorghum.

Polarization-division and spatial-division shared-aperture nanopatch antenna arrays for wide-angle optical beam scanning

Chip-based optical beam scanners hold promise for future compact high-speed light detection and ranging (LIDAR) systems. Many of the demonstrated chip-based optical beam scanners are designed based on diffraction-based waveguide gratings as on-chip antennas. The waveguide grating antenna, however, only provides a typical field-of-view (FOV) of roughly 10° by tuning the input light wavelength. In this paper, polarization-division and spatial-division multiplexed nanoantenna arrays are proposed to expand the FOV of on-chip antennas. The proposed device, based on silicon-on-insulator (SOI) platform, consists of three nanoantenna groups which are densely packed and fed by a common silicon nanostrip. It is demonstrated that the combination of the optical mode-multiplexing technique and the antenna engineering allows independent controls over the interactions between multiple nanoantenna groups and the waveguide. By proper engineering of the antenna dimensions, the proposed device achieves a FOV of over 40° within a 100 nm wavelength tuning range, almost tripling that of the conventional waveguide grating antenna.

[Significance of prostate central gland/total gland volume ratio combined with PSA in the diagnosis of prostate cancer patients]

Objective: To explore the significance of prostate central gland/total gland volume (PVc/PV) ratio combined with PSA in the diagnosis of PSA 4-20 ng/ml prostate cancer patients. Methods: Data of patients undergoing prostate puncture in Minghang Branch, Zhongshan Hospital from July 2015 to December 2018 were retrospectively analyzed. The anteroposterior, transverse and axial diameters of the prostate and the central prostate gland were measured by magnetic resonance imaging (MRI). The differences of tPSA, f/tPSA, PSAD and PVc/PV between the prostate cancer group and non-prostate cancer group were compared. Receiver operating characteristic (ROC) curves of prostate cancer diagnosis were plotted according to tPSA, f/tPSA, PSAD, PVc/PV alone and PVc/PV combined with tPSA, respectively, and the area under the curve (AUC) was calculated and compared using tPSA as the reference. Results: There was no significant difference in tPSA between the two groups (P>0.05). However, significant differences were observed in f/tPSA, PSAD and PVc/PV between the two groups (P<0.05). The AUC value of PVc/PV combined with tPSA, PVc/PV and PSAD was 0.901 2,0.866 7 and 0.848 1,respectively, which were statistically different from that of tPSA (P<0.05). The AUC value of f/tPSA was 0.716, which was not statistically different from that of tPSA (P>0.05). Conclusion: The PVc/PV ratio combined with tPSA can be used as an important reference index for the diagnosis of prostate cancer in PSA 4-20 ng/ml patients.

[Quality assessment of the clinical practice guideline for diagnosis, treatment and prevention of pulmonary thromboembolism, 2018]

Objective: To assess the quality of the clinical practice guideline for diagnosis, treatment and prevention of pulmonary thromboembolism, 2018 in China, providing the references for updating and developing clinical practice guidelines of this field in the future. Methods: The quality of the clinical practice guideline for diagnosis, treatment and prevention of pulmonary thromboembolism, 2018 in China was assessed using the internationally recognized instrument Appraisal of Guidelines for Research and Evaluation Ⅱ (AGREE Ⅱ). AGREE Ⅱ instrument consisted of 23 items in six domains, followed by two overall assessment items. Each item was scored from 1 to 7. The final overall guideline quality considered all domain items. Results: The scores of the six AGREE Ⅱ domains were: Scope and purpose 76.4%, Stakeholder involvement 55.6%, Rigor of development 78.1%, Clarity and presentation 83.3%, Applicability 55.2%, and Editorial independence 66.7%. The guideline was recommended for clinical use. Among the 101 recommendations, recommendations based on Levels High, Moderate and Low evidence accounted for 7 (6.9%), 31 (30.7%) and 63 (62.4%), respectively. Conclusion: The methodological quality of the clinical practice guideline for diagnosis, treatment and prevention of pulmonary thromboembolism, 2018 in China was great, but the levels of evidence were not high. More efforts were urgently required to improve in Stakeholder involvement and applicability. Especially corresponding economic research evidence, as well as preferences of patients and the public should be considered in the future development of clinical practice guidelines.

[The application of retroperitoneal laparoscopic nephron-sparing surgery in stage T(1b) renal cell carcinoma]

Objective: To investigate the safety and feasibility of retroperitoneal laparoscopic nephron-sparing surgery (NSS) in stage T(1b) renal cell carcinoma (RCC) patients . Methods: Between March 2014 and June 2017, 52 stage T(1b) RCC cases (36 males, 16 females) treated with retroperitoneal laparoscopic NSS in Zhongshan Hospital and Central Hospital of Minhang District were enrolled and retrospectively analyzed, with a tumor size range of 4.0 to 6.8 cm, and a mean size of(4.7±0.45)cm.The anatomic characteristics of tumors, operative time, intra-operative blood loss, warm ischemia time, intra- and post-operative complications, length of hospital stay, and oncological outcomes were reviewed. Results: Only 2 cases converted to open surgery due to uncontrollable bleeding in operation. The rest 50 cases successfully underwent retroperitoneal laparoscopic NSS, with mean operative time of (122±20.86) min (range: 100-220 min), mean blood loss of (140±128.85)ml (range: 50-800 ml), mean warm ischemia time of (30±3.52)min (range: 25-42 min), pre-operative mean serum creatinine of (100±23.54)μmol/L (range: 65-148 μmol/L), mean serum creatinine three monthsafter operation of (104±30.84)μmol/L (range: 72-224 μmol/L), mean drainage of (180±82.33)ml (range: 80-550 ml), mean length of hospital stay after operation of (8±1.56)d (range: 5-15 d). There was no significant difference in renal function between pre- and post-operation (P=0.056). One patient suffered pulmonary embolism was cured conservatively. Fifty patients were followed up, among which 47 cases with malignant pathology were followed up for 3-29 months, and two of them suffered from pulmonary metastasis. Conclusions: After pre-operative comprehensive assessment of tumors, stage T(1b) renal cell carcinoma could be treated with retroperitoneal laparoscopic NSS safely.

Boron difluoride hemicurcuminoid as an efficient far red to near-infrared emitter: toward OLEDs and laser dyes

A hemicurcuminoid boron difluoride complex is used as an emitter in organic light-emitting diodes, showing far red/near-infrared electroluminescence with an external quantum efficiency as high as 2.1%. This dye blended in CBP thin films shows amplified spontaneous emission with a threshold of 22 μJ cm^-2 at 750 nm, making this compound attractive for organic semiconductor lasers operating in the near-infrared region.

Intravital Imaging of Mouse Bone Marrow: Hemodynamics and Vascular Permeability

The bone marrow is a unique microenvironment where blood cells are produced and released into the circulation. At the top of the blood cell lineage are the hematopoietic stem cells (HSC), which are thought to reside in close association with the bone marrow vascular endothelial cells (Morrison and Scadden, Nature 505:327-334, 2014). Recent efforts at characterizing the HSC niche have prompted us to make close examinations of two distinct types of blood vessel in the bone marrow, the arteriolar vessels originating from arteries and sinusoidal vessels connected to veins. We found the two vessel types to exhibit different vascular permeabilites, hemodynamics, cell trafficking behaviors, and oxygen content (Itkin et al., Nature 532:323-328, 2016; Spencer et al., Nature 508:269-273, 2014). Here, we describe a method to quantitatively measure the permeability and hemodynamics of arterioles and sinusoids in murine calvarial bone marrow using intravital microscopy.

Image-guided transplantation of single cells in the bone marrow of live animals

Transplantation of a single hematopoietic stem cell is an important method for its functional characterization, but the standard transplantation protocol relies on cell homing to the bone marrow after intravenous injection. Here, we present a method to transplant single cells directly into the bone marrow of live mice. We developed an optical platform that integrates a multiphoton microscope with a laser ablation unit for microsurgery and an optical tweezer for cell micromanipulation. These tools allow image-guided single cell transplantation with high spatial control. The platform was used to deliver single hematopoietic stem cells. The engraftment of transplants was tracked over time, illustrating that the technique can be useful for studying both normal and malignant stem cells in vivo.

Intravital multiphoton photoconversion with a cell membrane dye

Photoconversion, an irreversible shift in a fluorophore emission spectrum after light exposure, is a powerful tool for marking cellular and subcellular compartments and tracking their dynamics in vivo. This paper reports on the photoconversion properties of Di-8-ANEPPS, a commercially available membrane dye. When illuminated with near-infrared femtosecond laser pulses, Di-8-ANEPPS undergoes multiphoton photoconversion as indicated by the supralinear dependence of the conversion rate ρ_pc on the incident power (ρpc∝Iexc2.27), and by the ability to photoconvert a thin optical section in a three-dimensional matrix. The characteristic emission spectrum changed from red to blue, and ratiometric analysis on single cells in vitro revealed a 65-fold increase in the blue to red wavelength ratio after photoconversion. The spectral shift is preserved in vivo for hours, making Di-8-ANEPPS a useful dye for intravital cell marking and tracking applications.

Electronic energy and electron transfer processes in photoexcited donor-acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units

We investigate the photophysical properties of organic donor-acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units linked by a non-conjugated flexible bridge in solution using complementary optical spectroscopy techniques. When these molecules are diluted in dichloromethane solution, energy transfer from the triphenylene to the perylene diimide excited moieties is evidenced by time-resolved fluorescence measurements resulting in a quenching of the emission from the triphenylene moieties. Simultaneously, another quenching process that affects the emission from both donor and acceptor units is observed. Solution ultrafast transient absorption measurements provide evidence of photo-induced charge transfer from either the donor or the acceptor depending upon the excitation. Overall, the analysis of the detailed time-resolved spectroscopic measurements carried out in the dyad and triad systems as well as in the triphenylene and perylene diimide units alone provides useful information both to better understand the relations between energy and charge transfer processes with molecular structures, and for the design of future functional dyad and triad architectures based on donor and acceptor moieties for organic optoelectronic applications.

[Analysis of early failure of the PHILOS in proximal humerus fractures]

OBJECTIVE

To analyze the reasons of early failure of the PHILOS in proximal humerus fractures.

METHODS

From Nov. 2010 to Nov. 2014, there were 117 patients with humerus fractures treated with PHILOS locking plate in Department of Orthopaedics, Xuanwu Hospital. All of the patients were treated with the plate by open reduction internal fixation, and we analyzed these cases retrospectively. After the operation, we removed the drainage tube within 48 h, and the patients were allowed to do the passive motion 3 days after the surgery if the X-Ray showed the plate and screws were reliable. Eight cases failed within 4 weeks after the operation. We analyzed the reasons of the failure.

RESULTS

The rate of the failed cases was 6.83%(8/117). The average age was 72.4(66-82) years. In the 8 failed cases, 3 were on the right side, and the other 5 on the left side. As for the reason of the fractures, 2 cases were because of car accidents, and the other 6 because of daily life injury. According to the Neer classification, 3 cases were 2-part fractures, and the other 5 3-part fractures. Three cases were total failure, and the other 5 partial failure. All the 8 failed cases failed within 4 weeks after the operation, of which 1 was on the sixth day after surgery, the other 7 2 to 4 weeks after the surgery.The 3 totally failed cases were treated by removing the screws and plates, the other 5 by conservative methods. All of the cases were malunion at the end.

CONCLUSION

The early failure of the PHILOS locking plate in proximal humerus fractures is related to the bad reduction during the operation, the loss of medial cortex support, the limitation of screw length, the osteoporosis and the improper rehabilitation after operation.It is very important to do good preoperative plan for a surgeon. During the operation, we should try our best in the fracture reduction, use the appropriate plate and screws, and then pay attention to the rehabilitation after the operation. After all of this, the rate of failure may be decreased.

Mie Resonance-Modulated Spatial Distributions of Photogenerated Carriers in Poly(3-hexylthiophene-2,5-diyl)/Silicon Nanopillars

Organic/silicon hybrid solar cells have great potential as low-cost, high-efficiency photovoltaic devices. The superior light trapping capability, mediated by the optical resonances, of the organic/silicon hybrid nanostructure-based cells enhances their optical performance. In this work, we fabricated Si nanopillar (NP) arrays coated with organic semiconductor, poly(3-hexylthiophene-2,5-diyl), layers. Experimental and calculated optical properties of the samples showed that Mie-resonance strongly concentrated incoming light in the NPs. Spatial mapping of surface photovoltage, i.e., changes in the surface potential under illumination, using Kelvin probe force microscopy enabled us to visualize the local behavior of the photogenerated carriers in our samples. Under red light, surface photovoltage was much larger (63 meV) on the top surface of a NP than on a planar sample (13 meV), which demonstrated that the confined light in the NPs produced numerous carriers within the NPs. Since the silicon NPs provide pathways for efficient carrier transportation, high collection probability of the photogenerated carriers near the NPs can be expected. This suggests that the optical resonance in organic/silicon hybrid nanostructures benefits not only broad-band light trapping but also efficient carrier collection.

[Analysis of early failure of the PHILOS in proximal humerus fractures]

OBJECTIVE

To analyze the reasons of early failure of the PHILOS in proximal humerus fractures.

METHODS

From Nov. 2010 to Nov. 2014, there were 117 patients with humerus fractures treated with PHILOS locking plate in Department of Orthopaedics, Xuanwu Hospital. All of the patients were treated with the plate by open reduction internal fixation, and we analyzed these cases retrospectively. After the operation, we removed the drainage tube within 48 h, and the patients were allowed to do the passive motion 3 days after the surgery if the X-Ray showed the plate and screws were reliable. Eight cases failed within 4 weeks after the operation. We analyzed the reasons of the failure.

RESULTS

The rate of the failed cases was 6.83%(8/117). The average age was 72.4(66-82) years. In the 8 failed cases, 3 were on the right side, and the other 5 on the left side. As for the reason of the fractures, 2 cases were because of car accidents, and the other 6 because of daily life injury. According to the Neer classification, 3 cases were 2-part fractures, and the other 5 3-part fractures. Three cases were total failure, and the other 5 partial failure. All the 8 failed cases failed within 4 weeks after the operation, of which 1 was on the sixth day after surgery, the other 7 2 to 4 weeks after the surgery.The 3 totally failed cases were treated by removing the screws and plates, the other 5 by conservative methods. All of the cases were malunion at the end.

CONCLUSION

The early failure of the PHILOS locking plate in proximal humerus fractures is related to the bad reduction during the operation, the loss of medial cortex support, the limitation of screw length, the osteoporosis and the improper rehabilitation after operation.It is very important to do good preoperative plan for a surgeon. During the operation, we should try our best in the fracture reduction, use the appropriate plate and screws, and then pay attention to the rehabilitation after the operation. After all of this, the rate of failure may be decreased.

Molecular Order of Arterial Collagen Using Circular Polarization Second-Harmonic Generation Imaging

Second-harmonic generation (SHG) originates from the interaction between upconverted fields from individual scatterers. This renders SHG microscopy highly sensitive to molecular distribution. Here, we aim to take advantage of the difference in SHG between aligned and partially aligned molecules to probe the degree of molecular order during biomechanical testing, independently of the absolute orientation of the scattering molecules. Toward this goal, we implemented a circular polarization SHG imaging approach and used it to quantify the intensity change associated with collagen fibers straightening in the arterial wall during mechanical stretching. We were able to observe the delayed alignment of collagen fibers during mechanical loading, thus demonstrating a simple method to characterize molecular distribution using intensity information alone.

Comparative transcriptome analysis of Nile tilapia (Oreochromis niloticus) in response to alkalinity stress

To identify genes of potential importance to alkalinity tolerance, RNA sequencing (RNA-Seq) was performed to survey gill transcriptome profiles from freshwater (FW) and alkaline water (AW) exposed Nile tilapia (Oreochromis niloticus). A total of 22,724,036 (AW)/16,461,040 (FW) single-end reads were generated in which 20,304,348 (AW)/14,681,290 (FW) reads (90.0/89.72%) were aligned to the reference genome. Differential expression analysis revealed 302 up-regulated and 193 down-regulated genes between AW- and FW-exposed fish. These differentially expressed genes were enriched in several Gene Ontology (GO) terms related to "stress response", "heme binding", and "carbonate dehydratase activity". Meanwhile, significant KEGG pathways were enriched in energy metabolism, including nitrogen and sulfur metabolism. These results demonstrate the response of Nile tilapia exposed to alkaline-water and might provide valuable information to further understand the molecular mechanisms of adaptation of fish to alkaline environments.

Resveratrol could reverse the expression of SIRT1 and MMP-1 in vitro

Intervertebral disc degeneration is the main cause of lumbago disease, in which the extracellular matrix structure and moisture in the nucleus pulposus is lost continuously. In this study, we aimed to detect differential expression of silence mating type information regulation 2 homolog 1 (SIRT1) and matrix metalloproteinase-1 (MMP-1) in human intervertebral disc nucleus pulposus cells and to explore the effects of SIRT1 and MMP-1 on the development of the intervertebral disc degeneration. Intervertebral disc nucleus pulposus specimens from 41 patients who underwent lumbar protrusion resection at HuiZhou Municipal Central Hospital, during the period from October 2011 to December 2013, were studied in comparison with 23 control cases from patients who underwent fractured lumbar resection. In degenerated human intervertebral disc nucleus pulposus cells, the expression of SIRT1 is decreased and MMP-1 is increased compared with that of the control cells. Resveratrol could reverse these effects, thereby increasing the expression of SIRT1 (0.87 ± 0.07 vs 0.54 ± 0.04), Coll2α1 (0.90 ± 0.08 vs 0.38 ± 0.01), and aggrecan (0.69 ± 0.07 vs 0.42 ± 0.05) and decreasing the expression of MMP-1 (0.61 ± 0.03 vs 0.93 ± 0.08). These results suggest that resveratrol could possibly reverse the process of intervertebral disc degeneration and thus could be applied as a potential drug for the disease.

Optical Properties of Laser Lines and Fluorescent Spectrum in Cholesteric Liquid Crystal Laser

We experimentally studied the comprehensive optical properties of the laser lines and fluorescent spectrum generated by a continuous tunable cholesteric liquid crystal (CLC) laser array. We found that the laser lines generated from a CLC with a right-handed circular helix were right-handed circular polarized and laser lines generated from a CLC with a left-handed circular helix were left-handed circular polarized. Inside the photonic band gap, the CLC structure with right-(left-) handed helicity suppressed the fluorescence generated with right (left) circular polarized light, and instead the suppressed right (left) circular polarized light energy moved to the outside of the photonic band gap, so we can say that the fluorescence intensity outside of the photonic band gap is enhanced with right (left) handed circular polarized light. Depending on the position of the photonic band gap, the fluorescence quantum yield value increased by up to ~15%. These enhanced fluorescence intensities at the PBG edge will evolve into lasing at the upper lasing threshold. It is particularly interesting to see that the fluorescence intensity and shape could be controlled by adjusting the external geometrical factor of the photonic band gaps. The lasing threshold of the CLC lasers was in the range of 1.5-5.3 μJ/pulse. For CLC laser device applications, it is necessary and essential to know the optical properties of the generated laser lines and of the fluorescence spectrum.

A novel frameshift mutation in the cylindromatosis (CYLD) gene in a Chinese family with multiple familial trichoepithelioma

Multiple familial trichoepithelioma (MFT) (OMIM: 601606) is an autosomal dominantly inherited disorder characterized by numerous, skin-colored papules and nodules with pilar differentiation. Recently, several mutations in the cylindromatosis (CYLD) gene have been reported in MFT. In this study, a mutation analysis of the CYLD was conducted in a Chinese pedigree of typical MFT. Affected individuals were identified through probands from Shanxi Province, China. Lesional skin biopsy of the proband revealed the typical histopathological characteristics of trichoepithelioma. Individuals belonging to five consecutive generations were similarly affected, which indicated an autosomal dominant inheritance pattern. Genomic DNA was extracted from peripheral blood lymphocytes using standard phenol/chloroform extraction method. All the coding exons (4-20) and exon-intron boundaries of the CYLD gene were amplified by polymerase chain reaction (PCR). Direct sequencing of all PCR products amplified from the complete coding regions of the CYLD gene was performed to identify mutations. Sequencing of the CYLD gene was performed in a further 100 unrelated, unaffected control individuals to exclude the possibility of polymorphism. A novel heterozygous frameshift mutation c.1169_1170delCA (p.Thr390Argfs) was identified in exon 10 of the CYLD gene in the affected family members. This mutation was also detected in unaffected family members, but not in the unrelated, healthy individuals who were also analyzed. Our study expands the database on the CYLD gene mutations in MFT and should be useful in providing genetic counseling and prenatal diagnosis for families affected by MFT.

Electro-optic switching in phase-discontinuity complementary metasurface twisted nematic cell

Electro-optic switching of refraction is experimentally demonstrated in a phase-discontinuity complementary metasurface twisted nematic cell. The phase-discontinuity complementary metasurface is fabricated by focused-ion-beam milling, and a twisted nematic cell is constructed with complementary V-shape slot antenna metasurface. By application of an external voltage, switching is achieved between ordinary refraction and extraordinary refraction satisfying the generalized Snell's law. It has a strong implication for applications in spatial light modulation and wavelength division multiplexer/demultiplexer in a near-IR spectral range.

Polarization-independent light emission enhancement of ZnO/Ag nanograting via surface plasmon polariton excitation and cavity resonance

In this study, we observed that the photoluminescence (PL) intensity of ZnO/Ag nanogratings was significantly enhanced compared with that of a planar counterpart under illumination of both transverse magnetic (TM) and transverse electric (TE)-mode light. In the TM mode, angle-resolved reflectance spectra exhibited dispersive dips, indicating cavity resonance as well as grating-coupled surface plasmon polariton (SPP) excitation. In the TE mode, cavity resonance only was allowed, and broad dips appeared in the reflectance spectra. Strong optical field confinement in the ZnO layers, with the help of SPP and cavity modes, facilitated polarization-insensitive PL enhancement. Optical simulation results were in good agreement with the experimental results, supporting the suggested scenario.

Enhanced nonlinear optical effects due to the excitation of optical Tamm plasmon polaritons in one-dimensional photonic crystal structures

We suggest optimally designed one-dimensional metal/photonic crystal structures for the excitation of optical Tamm plasmon polaritons, which show strongly enhanced electromagnetic field intensities compared to those due to conventional surface plasmon excitations. We assume that the photonic crystal is made of weakly nonlinear optical materials and calculate the reflectance and the electromagnetic field distribution precisely, using the invariant imbedding method generalized to nonlinear media. We find field intensity enhancement factors as large as 3,000 at the metal/photonic crystal interface. We verify that due to this strong enhancement, nonlinear optical effects such as optical bistability can be observed for very small values of the incident wave power. Our results imply that using our structure, very strong surface enhanced Raman scattering signals can be achieved and optical switching devices can be operated in much lower threshold light intensities.

Microsatellite markers in Paulownia kawakamii (Scrophulariaceae) and cross-amplification in other Paulownia species

Paulownia kawakamii is a fast-growing timber tree. In this study, 21 primer sets were developed using an enriched genomic library. The genetic diversity was measured in one P. kawakamii population. The number of alleles per locus ranged from 2 to 19. The observed and expected heterozygosities varied from 0.158 to 0.842 (mean = 0.421) and from 0.376 to 0.952 (mean = 0.771), respectively. All 21 loci were also polymorphic in closely related species (P. tomentosa, P. elongata, and P. fortunei). The described markers will be useful in future population genetic studies and molecular breeding of these Paulownia species.

Reflection resonance switching in metamaterial twisted nematics cell

Electric switching of reflection resonances at near-IR spectral range is experimentally demonstrated in a reflective metamaterial twisted nematic liquid crystal cell. Reflective metamaterial composed of nano-sized double-split ring resonator aperture is fabricated by a focused ion beam milling. Two-fold rotational symmetry of double-split ring resonators allows for two orthogonal polarization-dependent reflection resonances in the reflective metamaterial. With an external voltage of 10V across 12μm cell gap, a full switching is achieved between two reflection resonances. Dynamic measurements show the time constants of switch-on and switch-off are in the order of 100ms and 10ms, respectively.

Fabrication of polarization-dependent reflective metamaterial by focused ion beam milling

By focused ion beam milling, we fabricated near-IR reflective metamaterials consisting of nano-aperture arrays. Optimum parameters of ion beam current and accelerating voltage in the fabrication process are obtained. Nano-apertures constituting reflective metamaterial are successfully milled, and possess a reflective resonance in the near-IR spectral range. With a double-split-ring resonator structure for the nano-aperture, the intensity reflection at resonance is rendered polarization dependent. It is found that the point group symmetry of the nano-aperture array determines the amount of anisotropy in the intensity reflection. Finite-difference time-domain simulation was adopted to identify details of nano-aperture metastructures transferred from nano-aperture patterns by the focused ion beam milling.

Anisotropic change in THz resonance of planar metamaterials by liquid crystal and carbon nanotube

THz metamaterials are employed to examine changes in the meta-resonances when two anisotropic organic materials, liquid crystal and carbon nanotubes, are placed on top of metamaterials. In both anisotropic double split-ring resonators and isotropic four-fold symmetric split-ring resonators, anisotropic interactions between the electric field and organic materials are enhanced in the vicinity of meta-resonances. In liquid crystal, meta-resonance frequency shift is observed with the magneto-optical coupling giving rise to the largest anisotropic shift. In carbon nanotube, meta-resonance absorptions, parallel and perpendicular to nanotube direction, experience different amount of broadening of Lorentzian oscillator of meta-resonance. Investigation reported here opens the application of metamaterials as a sensor for anisotropic materials.

Cryogenic temperature measurement of THz meta-resonance in symmetric metamaterial superlattice

A symmetric metamaterial superlattice is introduced accommodating a high Q-factor trapped mode. THz time-domain spectroscopy is employed to measure the transmission spectra, identifying the excitation of trapped and open-modes in the meta-resonances. A finite-difference-time- domain calculation showed that the trapped mode excitation is from the cancelation of current densities among the nearest-neighboring meta-particles. A cryogenic temperature THz measurement is carried out to examine the temperature dependence of resonance characteristics of meta-resonances. At low temperatures, the temperature-independent radiative damping is dominant for the open-mode, while the Q-factor of the trapped mode is determined by the temperature-dependent phonon scattering and temperature-independent defect scattering with the radiative damping significantly suppressed. When compared with the room temperature measurement, a 16% increase in Q-factor is observed for the trapped mode, while a 7% increase for the open-mode at the cryogenic temperature.

Continuous spatial tuning of laser emissions with tuning resolution less than 1 nm in a wedge cell of dye-doped cholesteric liquid crystals

We report the design and fabrication of a wedge structured CLC film incorporating a spatial gradient of a chiral dopant concentration. A continuous spatial laser tuning in the broad visible spectral range with tuning resolution less than 1 nm is demonstrated, which renders a CLC-based micron-sized laser an important continuously tunable laser device.

Optical switching of near infrared light transmission in metamaterial-liquid crystal cell structure

A metamaterial-liquid crystal cell structure is fabricated with the metamaterial as one of the liquid crystal alignment layers. Nano-sized double-split ring resonator in the metamaterial accommodates two distinct resonances in the near infrared regime. By adopting an azo-nematic liquid crystal in a twisted nematic liquid crystal cell structure, a photo-isomerization process is utilized to achieve an optical switching of light transmissions between two resonances. A single device of the metamaterial-liquid crystal cell structure has a potential application in the photonic switching in optical fiber telecommunications.

Polarization angle control of coherent coupling in metamaterial superlattice for closed mode excitation

A superlattice structure of planar metamaterial is fabricated, where the orientation of double-split ring resonators is altered in a periodic way. A time-domain terahertz transmission spectrum shows an enhanced Q-factor resonance appears when a closed mode is selectively excited by angular tuning of polarization direction. The polarization-angle selective resonance in metamaterial superlattice has a potential application in the selective field enhancement for spectroscopy.

In vivo imaging of hematopoietic stem cells and their microenvironment

In this review we provide a description of the basic concepts and paradigms currently constituting the foundations of adult stem cell biology, and discuss the role that live imaging techniques have in the development of the field. We focus on live imaging of hematopoietic stem cells (HSCs) as the basic biology and clinical applications of HSCs have historically been at the forefront of the stem cell field, and HSC are the first mammalian tissue stem cells to be visualized in vivo using advanced light microscopy techniques. We outline the current technical challenges that remain to be overcome before stem cells and their niche can be more fully characterized using the live imaging technology.

Photoinduced circular anisotropy in a photochromic W-shaped-molecule-doped polymeric liquid crystal film

Photoinduced circular anisotropy has been demonstrated in thin films of a main-chain polymeric liquid crystal (PLC) system doped with photochromic W-shaped molecules containing two azobenzene groups by irradiating with circularly polarized light (CPL). Reversible photoinduced circular dichroism (CD) was observed with sign relevant to the handedness of the CPL. The experimentally observed CD spectra were analyzed using the DeVoe polarizability model associated with the coupled oscillator method. We also propose a mechanism for the photoinduced circular anisotropy in our system; nucleating the W-shaped molecules with preferential twisted conformation by CPL irradiation, and triggering the local formation of a chiral structure in the W-shaped-molecule-doped main-chain PLC medium.

Picosecond pump-probe measurement of bandgap changes in SiO2/TiO2 one-dimensional photonic bandgap structures

A picosecond pump-probe nonlinear optical measurement is performed in SiO2/TiO2 one-dimensional photonic bandgap structures fabricated by a solgel method. Both high and low band edges were examined by varying the probe wavelengths and angle tuning was also employed to further clarify the mechanism of a nonlinear optical response. The third-order nonlinear optical response in one-dimensional photonic bandgap structures that comprise TiO2 films is responsible for the nonlinear optical transmissions at both bandgap edges, with an 8% decrease at the low-energy edge and a 4.5% increase at the high-energy edge for a 355 nm pump intensity of 430 MW/cm2.

Analysis of surface second-harmonic generation by orientational distribution function in a chiral polymer film

By adopting classical models of molecular chirality, contributions of the coupled-oscillator and helix natures to the chiral surface second-order susceptibilities are identified through introduction of a molecular orientational distribution. Experimentally, surface orientational distribution functions at interfaces of an isotropic chiral chitosan polymer film are determined from second harmonic generation measurement. The largest chiral component of surface nonlinear optical susceptibility is from the electric-magnetic coupling with dominant contribution from the helix nature of chitosan.

In vivo imaging of specialized bone marrow endothelial microdomains for tumour engraftment

The organization of cellular niches is known to have a key role in regulating normal stem cell differentiation and regeneration, but relatively little is known about the architecture of microenvironments that support malignant metastasis. Using dynamic in vivo confocal imaging, here we show that murine bone marrow contains unique anatomic regions defined by specialized endothelium. This vasculature expresses the adhesion molecule E-selectin and the chemoattractant stromal-cell-derived factor 1 (SDF-1) in discrete, discontinuous areas that influence the homing of a variety of tumour cell lines. Disruption of the interactions between SDF-1 and its receptor CXCR4 inhibits the homing of Nalm-6 cells (an acute lymphoblastic leukaemia cell line) to these vessels. Further studies revealed that circulating leukaemic cells can engraft around these vessels, suggesting that this molecularly distinct vasculature demarcates a microenvironment for early metastatic tumour spread in bone marrow. Finally, purified haematopoietic stem/progenitor cells and lymphocytes also localize to the same microdomains, indicating that this vasculature might also function in benign states to demarcate specific portals for the entry of cells into the marrow space. Specialized vascular structures therefore appear to delineate a microenvironment with unique physiology that can be exploited by circulating malignant cells.

Electro-tunable optical diode based on photonic bandgap liquid-crystal heterojunctions

Manipulation of light is in strong demand in information technologies. Among the wide range of linear and nonlinear optical devices that have been used, growing attention has been paid to photonic crystals that possess a periodic modulation of dielectric function. Among many photonic bandgap (PBG) structures, liquid crystals with periodic structures are very attractive as self-assembled photonic crystals, leading to optical devices such as dye lasers. Here we report a new hetero-PBG structure consisting of an anisotropic nematic layer sandwiched between two cholesteric liquid-crystal layers with different helical pitches. We optically visualized the dispersion relation of this structure, displaying the optical diode performance: that is, the non-reciprocal transmission of circular polarized light at the photonic-bandgap regions. Transmittance spectra with circularly polarized light also reveal the diode performance, which is well simulated in calculations that include an electro-tunable diode effect. Lasing action was also confirmed to show the diode effect with a particular directionality.

Determination of optical Kerr nonlinearity of a photonic bandgap structure by Z-scan measurement

Through analysis of the dispersion relation in a photonic bandgap structure, the effective optical Kerr nonlinearity that determines a Z-scan profile particularly near the stop-band edges, is derived. Near and inside the stop band, the nonlinear optical phase change that originates from an off-resonant response is converted into a change in nonlinear optical intensity through Bragg reflection. The Z-scan measurement of a cholesteric liquid-crystal photonic bandgap structure confirmed that off-resonant Kerr nonlinearity is responsible for the characteristic open-aperture Z-scan profiles near the stop-band edges.

Twist-grain-boundary structure in the B4 phase of a bent-core molecular system identified by second harmonic generation circular dichroism measurement

Second harmonic generation circular dichroism (SHG CD) measurements are performed on the B4 phase of a bent-core molecular system. Numerical analysis of SHG CD incorporating magnetic-dipole as well as electric-dipole interaction shows that the B4 phase is in a twist-grain-boundary structure with the helical axis along the bent direction of the molecules. The result is extremely important in the sense that achiral molecules are spontaneously optically resolved, i.e., deracemization, the chiral domains of which give rise to huge chiral nonlinear optical effect.

Microstructure of a poled surface-relief grating and its electro-optic response

The microstructure of a poled surface-relief grating of an azobenzene side-chain polymer film is investigated. From the in situ monitoring of diffraction efficiency and second-harmonic generation, as well as dynamic-contact electrostatic force microscopy images, the point group symmetry of C2nu is identified. The polarization-dependent electro-optic measurement of the reflected diffraction order further confirms the optically biaxial structure of the poled surface-relief grating.

Enhanced optical nonlinearity near the photonic bandgap edges of a cholesteric liquid crystal

The third-order Kerr nonlinear optical effect of a one-dimensional photonic bandgap structure of a cholesteric liquid crystal is investigated. In a femtosecond nonlinear transmission measurement, nonlinear optical changes in the bandgap edges are observed. From analysis of the dispersion relation, Kerr nonlinear coefficients of nematics, forming the cholesteric liquid crystal, are found to be enhanced by 1-2 orders of magnitude through the photonic bandgap structure.