Nanowire Waveguides and Lasers: Advances and Opportunities in Photonic Circuits

Due to their single-crystalline structures, comparatively large aspect ratios, tight optical confinement and smooth surfaces, nanowires have increasingly attracted research interests for both fundamental studies and technological applications in on-chip photonic devices. This class of nanostructures typically have cross-sections of 2~200 nm and lengths upwards of several micrometers, allowing for the bridging of the nanoscopic and macroscopic world. In particular, the lasing behaviors can be established from a nanowire resonator with positive feedback via end-facet reflection, making the nanowire a promising candidate in the next generation of optoelectronics. Consequently, versatile nanowire-based devices ranging from nanoscale coherent lasers, optical sensors, waveguides, optical switching, and photonic networks have been proposed and experimentally demonstrated in the past decade. In this article, significant progresses in the nanowire fabrication, lasers, circuits, and devices are reviewed. First, we focus on the achievements of nanowire synthesis and introduce the basics of nanowire optics. Following the cavity configurations and mode categories, then the different light sources consisting of nanowires are presented. Next, we review the recent progress and current status of functional nanowire devices. Finally, we offer our perspective of nanowires regarding their challenges and future opportunities in photonic circuits.

Optical Fiber Sensors by Direct Laser Processing: A Review

The consolidation of laser micro/nano processing technologies has led to a continuous increase in the complexity of optical fiber sensors. This new avenue offers novel possibilities for advanced sensing in a wide set of application sectors and, especially in the industrial and medical fields. In this review, the most important transducing structures carried out by laser processing in optical fiber are shown. The work covers different types of fiber Bragg gratings with an emphasis in the direct-write technique and their most interesting inscription configurations. Along with gratings, cladding waveguide structures in optical fibers have reached notable importance in the development of new optical fiber transducers. That is why a detailed study is made of the different laser inscription configurations that can be adopted, as well as their current applications. Microcavities manufactured in optical fibers can be used as both optical transducer and hybrid structure to reach advanced soft-matter optical sensing approaches based on optofluidic concepts. These in-fiber cavities manufactured by femtosecond laser irradiation followed by chemical etching are promising tools for biophotonic devices. Finally, the enhanced Rayleigh backscattering fibers by femtosecond laser dots inscription are also discussed, as a consequence of the new sensing possibilities they enable.

Prevalence of invasive aspergillosis in suspected pulmonary tuberculosis at a referral tuberculosis hospital in Shandong, China

Although the progression of invasive aspergillosis (IA) shares some risk factors in the development of active pulmonary tuberculosis (PTB), however, the prevalence of IA in suspected PTB remains unclear. During a period of 1 year (from January 2016 to December 2016), consecutive patients with suspected PTB were included in a referral TB hospital. Data, including demographic information and underlying diseases, were collected from medical records. PTB were all confirmed by mycobacterial culture (Lowenstein–Jensen medium). IA were diagnosed as proven or probable according to the criteria of the 2008 EORTC/MSG definitions. A descriptive analysis was performed to estimate the corresponding prevalence. During the study year, 1507 patients have a positive mycobacterial culture, with a mean age of 45.6 (s.d. 19.9) years old and a female:male ratio of 1:4. Among the 82 patients with non-tuberculous mycobacterial diseases, two patients (2.44%, 95% CI 0.67–8.46%) were diagnosed as IA (one proven and one probable); two probable IA patients (0.15%, 95% CI 0.04–0.55%) were diagnosed in PTB patients (n = 1315), and all were retreatment cases. In addition, all four IA patients (100%) exhibited cavities in both lobes on radiograph. In China, the prevalence of IA is low in active PTB patients. However, when high-risk factors for IA are encountered in PTB patients, further investigations are required and empirically treatment for IA might be warranted.

Bronchoscopic visualization of a cavity in entirety: an unusual finding

It is unusual to be able to visualize an entire cavity with such clarity.

Structural cavities are critical to balancing stability and activity of a membrane-integral enzyme

Packing interaction is a critical driving force in the folding of helical membrane proteins. Despite the importance, packing defects (i.e., cavities including voids, pockets, and pores) are prevalent in membrane-integral enzymes, channels, transporters, and receptors, playing essential roles in function. Then, a question arises regarding how the two competing requirements, packing for stability vs. cavities for function, are reconciled in membrane protein structures. Here, using the intramembrane protease GlpG of Escherichia coli as a model and cavity-filling mutation as a probe, we tested the impacts of native cavities on the thermodynamic stability and function of a membrane protein. We find several stabilizing mutations which induce substantial activity reduction without distorting the active site. Notably, these mutations are all mapped onto the regions of conformational flexibility and functional importance, indicating that the cavities facilitate functional movement of GlpG while compromising the stability. Experiment and molecular dynamics simulation suggest that the stabilization is induced by the coupling between enhanced protein packing and weakly unfavorable lipid desolvation, or solely by favorable lipid solvation on the cavities. Our result suggests that, stabilized by the relatively weak interactions with lipids, cavities are accommodated in membrane proteins without severe energetic cost, which, in turn, serve as a platform to fine-tune the balance between stability and flexibility for optimal activity.

Association Between Duration of Aminoglycoside Treatment and Outcome of Cavitary Mycobacterium avium Complex Lung Disease

BACKGROUND

Although aminoglycosides are recommended for cavitary Mycobacterium avium complex lung disease (MAC-LD), the optimal duration of treatment is unclear. We investigated the association between duration of aminoglycoside treatment and outcomes in cavitary MAC-LD.

METHODS

Among patients diagnosed with macrolide-susceptible cavitary MAC-LD between 2000 and 2013, 101 who received treatment up to August 2017 with a regimen containing aminoglycosides were enrolled at a tertiary referral center in South Korea. Their medical records were retrospectively reviewed. The duration of aminoglycoside treatment was at the discretion of the attending physician.

RESULTS

A total of 75 patients (74.3%) were administered aminoglycosides for ≥3 months (median 164 days), whereas the remaining 26 patients (25.7%) received treatment for <3 months (median 59 days). The overall treatment success rate was 63.4% (64/101). Patients treated with aminoglycosides for ≥3 months had a significantly higher success rate than those treated for <3 months (69.3% vs 46.2%; P = .035). Multivariate analysis revealed that aminoglycoside treatment for ≥3 months was a significant factor for treatment success (adjusted odds ratio, 3.602; 95% confidence interval, 1.249-10.390; P = .018). Recurrence occurred in 8 (22.9%) of 35 patients who were followed up for at least 3 years after the end of treatment; all 8 patients received aminoglycosides for ≥3 months.

CONCLUSIONS

Patients with cavitary MAC-LD treated with aminoglycosides for ≥3 months showed higher treatment success rate than those treated for <3 months. However, treatment for ≥3 months was not associated with the development of recurrence.

Numerical Investigation on the Optimum Thermal Design of the Shape and Geometric Parameters of Microchannel Heat Exchangers with Cavities

Due to the large surface-area-to-volume ratio, microchannel heat exchangers have a higher heat transfer rate compared with traditional scale heat exchangers. In this study, the optimum microchannel cavity with high heat transfer and low flow resistance is designed to further improve microchannel exchangers' thermal performance. A three-dimensional laminar flow model, consisting of Navier-Stokes equations and an energy conservation equation is solved and the conjugate heat transfer between the silicon basement and deionized water is taken into consideration. The impact of the shape, aspect ratio, size and spacing of the cavity on the thermal performance of microchannel exchangers are numerically investigated, respectively. The results indicated that the cavity on the sidewall can enhance heat transfer and reduce flow resistance simultaneously, and cavities with a relatively small expansion angle and streamlined edge could enhance thermal performance the most. Based on the conclusions, a new cavity shape is proposed, and the simulation results verify its excellent thermal performance as expected. Furthermore, investigation is performed to figure out the optimum design of the new cavity and the optimal geometric parameters of the cavity under different flow conditions have been obtained in principle for microchannel exchangers' design.

An uncommon manifestation of COVID-19 pneumonia on CT scan with small cavities in the lungs: A case report

RATIONALE

Chest computed tomography (CT) scans play a key role in diagnosing and managing of COVID-19 pneumonia. The typical manifestations of COVID-19 pneumonia on a chest CT scan are ground glass opacities, consolidation, nodules, and linear opacities. It can be accompanied by a "crazy-paving" pattern, air bronchograms, pleural hypertrophy, and pleural effusion. However, no literature has reported a case with cavities in the lungs.

PATIENT CONCERNS

A 34-year-old male patient complained of fever, cough, fatigue, myalgia, diarrhea, headache, and dizziness for 2 weeks. This patient is living in Xiaogan, a city around Wuhan, and he had contact with a patient with COVID-19 pneumonia from Wuhan <14 days before he had fever.

DIAGNOSIS

A nucleic acid test by rRT-PCR returned positive on a pharyngeal swab, confirming the diagnosis of COVID-19 pneumonia.

INTERVENTIONS

Isolation antiviral treatment.

OUTCOMES

After 19 days of isolation and antiviral treatment, his temperature returned to normal and the symptoms were relieved. The laboratory results also were returning to normal levels. The chest CT scan showed that the acute inflammation had subsided significantly. With 2 consecutive novel coronavirus nucleic acid tests had returned negative, the patient was discharged from the hospital and sent to a government designated hotel for quarantine observation. The unique chest CT manifestation in this case was the small cavities in both lungs during the absorption phase of this disease. These small cavities developed into consolidated nodules with clear edges and gradually shrank or disappeared.

LESSONS

Although 2 consecutive nucleic acid tests returned negative in this patient, the small cavity changes in the lungs were observed, so the patient was quarantined for 14 days. However, follow-up CT after the first 14 days' quarantine showed new small cavity changes on the lungs, a further 14 days of quarantine was recommended. Therefore, in some COVID-19 cases, even if the nucleic acid tests turns negative, the disappearance of lung lesions may take a long time. The repeated chest CT scan plays an important role in the diagnosis and evaluation of the recovery of COVID-19.

Conserved buried water molecules enable the β-trefoil architecture

Available high-resolution crystal structures for the family of β-trefoil proteins in the structural databank were queried for buried waters. Such waters were classified as either: (a) unique to a particular domain, family, or superfamily or (b) conserved among all β-trefoil folds. Three buried waters conserved among all β-trefoil folds were identified. These waters are related by the threefold rotational pseudosymmetry characteristic of this protein architecture (representing three instances of an identical structural environment within each repeating trefoil-fold motif). The structural properties of this buried water are remarkable and include: residing in a cavity space no larger than a single water molecule, exhibiting a positional uncertainty (i.e., normalized B-factor) substantially lower than the average Cα atom, providing essentially ideal H-bonding geometry with three solvent-inaccessible main chain groups, simultaneously serving as a bridging H-bond for three different β-strands at a point of secondary structure divergence, and orienting conserved hydrophobic side chains to form a nascent core-packing group. Other published work supports an interpretation that these interactions are key to the formation of an efficient folding nucleus and folded thermostability. The fundamental threefold symmetric structural element of the β-trefoil fold is therefore, surprisingly, a buried water molecule.

Viscous flow and collapse of macroscopic cavities in a granular material in terms of a Darcylet

Viscous flow through a granular material that has a macroscopic cavity is obtained on the basis of the Stokes and the generalized Darcy's equation. A new singularity termed 'Darcylet', a fundamental flow in the granular material that acts like a point force with negative direction, is proposed, which is applied to elucidate the interaction of two cavities. Depending on the configuration of the latter, the volume flux into the cavity increases, which enhances the local stresses on the boundary, causes the collapse of cavities and triggers landslides. This article is part of the theme issue 'Stokes at 200 (Part 1)'.

Analysis of the Extreme Equilibrium Conditions of an Internal Cavity Located Inside a Flat Metal Plate Subjected to an Internal Pressure p

The influence of surface bulges and cavities within metals is an important metallurgical-mechanical problem that has not been fully solved and motivates multiple discussions. This is not only related to the generation of interfaces, but also to the distribution of alloying components and elements. In this study, Laplace's equation was used to develop a set of equations to describe these kinds of defects in plates, which arise during the development of metallurgical processes, and this can be used for the prediction of pipeline failures subjected to internal pressure. In addition, the stability conditions of a cavity under an internal pressure are analyzed. The developed method allows to identify the stress state in the generation of the cavity and its propagation. In addition to this, finite element analyses were carried out in order to show first the stress distribution around a cavity subjected to a series of theoretical operation conditions and second to show the crack growth on the tip of the cavity.

Mercaptothiacalixarenes Steer 24 Copper(I) Centers to form a Hollow-Sphere Structure Featuring Cu2 S2 Motifs with Exceptionally Short Cu⋅⋅⋅Cu Distances

Tetramercaptotetrathiacalix[4]arene (LH₄) can be used as a coordination platform to bind four Cu^I ions at the thiolate and thioether S atoms. Donor ligands such as phosphanes can stabilize the resulting [LCu₄] units, which then remain monomeric ([(Ph₃PCu)₄L]). In the absence of donor ligands, they aggregate, providing a hexamer ([LCu₄]₆) in high yields, with a hollow‐sphere structure formed by an unprecedented Cu₂₄S₄₈ cage that is surrounded by the organic framework of the calixarene chalices. Preliminary NMR experiments with regard to the host‐guest chemistry in solution showed that the compound represents a polytopic host for acetonitrile and methane.

Numerical Simulation on Convection and Thermal Radiation of Casson Fluid in an Enclosure with Entropy Generation

The goal of the current numerical simulation is to explore the impact of aspect ratio, thermal radiation, and entropy generation on buoyant induced convection in a rectangular box filled with Casson fluid. The vertical boundaries of the box are maintained with different constant thermal distribution. Thermal insulation is executed on horizontal boundaries. The solution is obtained by a finite volume-based iterative method. The results are explored over a range of radiation parameter, Casson fluid parameter, aspect ratio, and Grashof number. The impact of entropy generation is also examined in detail. Thermal stratification occurs for greater values of Casson liquid parameters in the presence of radiation. The kinetic energy grows on rising the values of Casson liquid and radiation parameters. The thermal energy transport declines on growing the values of radiation parameter and it enhances on rising the Casson fluid parameter.

Design of Substrate-Integrated Waveguide Loading Multiple Complementary Open Resonant Rings (CSRRs) for Dielectric Constant Measurement

In order to solve the low-sensitivity problem of the dielectric constant with the resonant cavity method, a sensor based on a substrate-integrated waveguide structure loaded with a multi-complementary open resonant ring is proposed. With the enhanced resonance characteristics of the sensor, this design realized the measurement of complex dielectric constants in a wide range. The frequency selectivity of the sensor is improved by the high-quality factor of the substrate-integrated waveguide. By loading three complementary resonant rings with different opening directions in the ground plane, a deeper notch and better out-of-band suppression are achieved. The effect of the complex dielectric constant on both resonant frequency and quality factor is discussed by calculating the material under test with a known dielectric constant. Simulation and experimental results show that a resonance frequency offset of 102 MHz for the per unit dielectric constant is achieved. A wide frequency offset is the prerequisite for accurate measurement. The measurement results of four plates match well with the standard values, with a relative error of the real part of the dielectric constant of less than 2% and an error of less than 0.0099 for the imaginary part.

Overexpression of HvCslF6 in barley grain alters carbohydrate partitioning plus transfer tissue and endosperm development

In cereal grain, sucrose is converted into storage carbohydrates: mainly starch, fructan, and mixed-linkage (1,3;1,4)-β-glucan (MLG). Previously, endosperm-specific overexpression of the HvCslF6 gene in hull-less barley was shown to result in high MLG and low starch content in mature grains. Morphological changes included inwardly elongated aleurone cells, irregular cell shapes of peripheral endosperm, and smaller starch granules of starchy endosperm. Here we explored the physiological basis for these defects by investigating how changes in carbohydrate composition of developing grain impact mature grain morphology. Augmented MLG coincided with increased levels of soluble carbohydrates in the cavity and endosperm at the storage phase. Transcript levels of genes relating to cell wall, starch, sucrose, and fructan metabolism were perturbed in all tissues. The cell walls of endosperm transfer cells (ETCs) in transgenic grain were thinner and showed reduced mannan labelling relative to the wild type. At the early storage phase, ruptures of the non-uniformly developed ETCs and disorganization of adjacent endosperm cells were observed. Soluble sugars accumulated in the developing grain cavity, suggesting a disturbance of carbohydrate flow from the cavity towards the endosperm, resulting in a shrunken mature grain phenotype. Our findings demonstrate the importance of regulating carbohydrate partitioning in maintenance of grain cellularization and filling processes.

Fungal pneumonia manifesting as cavitary lesions in a critically ill elderly patient

Elderly patients with fungal pneumonia experience higher mortality and are more likely to be misdiagnosed. The diagnosis and treatment of fungal pneumonia in elderly patients is challenging. We herein present a clinical case of pulmonary fungal infection (PFI) manifesting as cavitary lesions in an 85-year-old male with multiple organ failure. Broad-spectrum antibiotics showed unsatisfactory result in this case. Computed tomography (CT) of the chest showed multiple pulmonary cavities with gas-fluid levels in the right upper and middle lobe, and patchy blurred shadows in the lower lobe. The diagnosis of fungal pneumonia was made after ruling out other causes of fever. The patient showed good response to anti-fungal treatment. Physicians must consider the possibility of fungal pneumonia in elderly patients who do not respond to antibiotic treatment after exclusion of immune response, tumor, tuberculosis, and other systemic infections.

Detection of cave pockets in large molecules: Spaces into which internal probes can enter, but external probes from outside cannot

Geometric features of macromolecular shapes are important for binding with other molecules. Kawabata, T. and Go, N. (2007) defined a pocket as a space into which a small probe can enter, but a large probe cannot. In 2010, mathematical morphology (MM) was introduced to provide a more rigorous definition, and the program GHECOM was developed using the grid-based representation of molecules. This method was simple, but effective in finding the binding sites of small compounds on protein surfaces. Recently, many 3D structures of large macromolecules have been determined to contain large internal hollow spaces. Identification and size estimation of these spaces is important for characterizing their function and stability. Therefore, we employ the MM definition of pocket proposed by Manak, M. (2019)—a space into which an internal probe can enter, but an external probe cannot enter from outside of the macromolecules. This type of space is called a “cave pocket”, and is identified through molecular grid-representation. We define a “cavity” as a space into which a probe can enter, but cannot escape to the outside. Three types of spaces: cavity, pocket, and cave pocket were compared both theoretically and numerically. We proved that a cave pocket includes a pocket, and it is equal to a pocket if no cavity is found. We compared the three types of spaces for a variety of molecules with different-sized spherical probes; cave pockets were more sensitive than pockets for finding almost closed internal holes, allowing for more detailed representations of internal surfaces than cavities provide.

Radiological difference between new sputum-positive and sputum-negative pulmonary tuberculosis

Introduction:

The current guidelines for the diagnosis of pulmonary tuberculosis (PTB) are based primarily on the demonstration of acid-fast bacilli (AFB) on sputum microscopy and chest radiograph. Knowing various radiological manifestations and their association with sputum microscopy findings can allow for early diagnosis and early initiation of treatment.

Aims:

This study was performed to compare the chest radiograph features seen in sputum-positive and sputum-negative tuberculosis patients, respectively.

Materials and Methods:

It was a prospective observational study, which included 147 consecutive patients newly diagnosed and treated as PTB between Jan 2018 and July 2018. Chest X-ray was reviewed by 2 independent radiologists and the findings were compared between sputum-positive and sputum-negative PTB cases. The obtained data were analyzed by statistics using SPSS version 15 for Windows (SPSS Inc., Chicago, IL) and χ² test and Student t test were used for statistical analysis. P values < 0.05 were considered statistically significant.

Results:

Out of a total of 147 patients, 38 (25 males and 13 females, mean age 35.23 ± 18.40) were sputum positive and 109 (77 males and 32 females, mean age 36.07 ± 18.15) were sputum negative. The frequency of patchy consolidation (78.94% vs 49.54%) and cavitation (36.84% vs 15.59%) was significantly higher in sputum-positive PTB (P < 0.05). Radiological lesions like nodular shadow (10.09% vs 2.63%), cystic lesion (13.76% vs 5.26%), fibrosis (12.84% vs 7.89%), miliary shadows (2.75% vs 2.63%), and pleural effusion (1.83% vs 0%) were seen more commonly with sputum-negative PTB but the difference was not statistically significant for any of these features. Sputum-positive PTB tends to occur more commonly on the left side (47.36%) compared with sputum-negative PTB (27.52%) (P < 0.05). 34.21% and 35.77% of the chest X-ray lesions were bilateral in sputum-positive and sputum-negative PTB, respectively.

Conclusion:

Patchy infiltration and cavitation on chest X-ray are seen more frequently in sputum-positive cases of PTB compared with sputum-negative cases.

Coexistence of nontuberculous mycobacterium and IgG4-related disease in a solitary pulmonary nodule: A case report

RATIONALE

Immunoglobulin G4-related disease (IgG4-RD) is regarded as an immune-mediated systemic fibroinflammatory disease. Several studies have linked IgG4-RD to infections such as tuberculosis and actinomycosis. However, the coexistence of IgG4-RD and non-tuberculous mycobacterium (NTM) in a single pulmonary nodule has not been reported yet.

PATIENT CONCERNS

A 76-year-old male patient presented with cough and sputum. A solitary pulmonary nodule suspicious of lung cancer was found on chest CT.

DIAGNOSIS

Through video-assisted thoracoscopic biopsy, a diagnosis of co-existing NTM and IgG4-RD in a single nodule was made.

INTERVENTIONS

Antibiotic treatment was applied for pneumonia developed after surgery. The patient was also supported by extracorporeal membrane oxygenation and mechanical ventilation since his pneumonia was refractory to medical treatment.

OUTCOMES

The patient expired on the 60th postoperative day due to multiple organ failure.

LESSONS

IgG4-RD can occur singularly or accompanied by other diseases. We report a solitary pulmonary nodule caused by NTM and concurrent IgG4-RD, suggesting a possible association between these 2 entities. Immunologic relations between IgG4-RD and accompanying infection should be further investigated.

Observation of Rydberg exciton polaritons and their condensate in a perovskite cavity

The condensation of half-light half-matter exciton polaritons in semiconductor optical cavities is a striking example of macroscopic quantum coherence in a solid-state platform. Quantum coherence is possible only when there are strong interactions between the exciton polaritons provided by their excitonic constituents. Rydberg excitons with high principal value exhibit strong dipole-dipole interactions in cold atoms. However, polaritons with the excitonic constituent that is an excited state, namely Rydberg exciton polaritons (REPs), have not yet been experimentally observed. Here, we observe the formation of REPs in a single crystal CsPbBr₃ perovskite cavity without any external fields. These polaritons exhibit strong nonlinear behavior that leads to a coherent polariton condensate with a prominent blue shift. Furthermore, the REPs in CsPbBr₃ are highly anisotropic and have a large extinction ratio, arising from the perovskite's orthorhombic crystal structure. Our observation not only sheds light on the importance of many-body physics in coherent polariton systems involving higher-order excited states, but also paves the way for exploring these coherent interactions for solid-state quantum optical information processing.

Design of Cavity-Backed Bow-Tie Antenna with Matching Layer for Human Body Application

This paper presents the broadband antenna for the microwave radiometric sensing of internal body temperature. For broadband operation, the bow-tie antenna was designed and backed with a cylindrical cavity, which decreased environmental electromagnetic interference and also improved the directivity of the antenna. The broadband impedance-transforming balun in microstrip form was also designed to feed the bow-tie antenna, and was located inside the cavity. An impedance-matching dielectric layer (IMDL) was introduced on top of the bow-tie antenna, for impedance match with the human body with high permittivity. The fabricated antenna was measured in free space with the IMDL removed, showing an input reflection coefficient lower than -10 dB from 2.64 to > 3.60 GHz with antenna gain over 6.0 dBi and radiation efficiency over 74.7% from 2.7 to 3.5 GHz. The IMDL was re-installed on the cavity-backed bow-tie antenna to measure the antenna performance for the human head with relative permittivity of about 40. The measured reflection coefficient was as low as -28.9 dB at 2.95 GHz and lower than -10 dB from 2.65 to > 3.5 GHz. It was also shown that the designed antenna recovered a good impedance match by adjusting the permittivity and thickness of the IMDL for the different parts of the human body with different permittivities.

Voronoi-based detection of pockets in proteins defined by large and small probes

The function of enzymatic proteins is given by their ability to bind specific small molecules into their active sites. These sites can often be found in pockets on a hypothetical boundary between the protein and its environment. Detection, analysis, and visualization of pockets find its use in protein engineering and drug discovery. Many definitions of pockets and algorithms for their computation have been proposed. Kawabata and Go defined them as the regions of empty space into which a small spherical probe can enter but a large probe cannot and developed programs that can compute their approximate shape. In this article, this definition was slightly modified in order to capture the existence of large internal holes, and a Voronoi-based method for the computation of the exact shape of these modified regions is introduced. The method first puts a finite number of large probes on the protein exterior surface and then, considering both large probes and atomic balls as obstacles for the small probe, the method computes the exact shape of the regions for the small probe. This is all achieved with Voronoi diagrams, which help with the safe navigation of spherical probes among spherical obstacles. Detected regions are internally represented as graphs of vertices and edges describing possible movements of the center of the small probe on Voronoi edges. The surface bounding each region is obtained from this representation and used for visualization, volume estimation, and comparison with other approaches. © 2019 Wiley Periodicals, Inc.

Spatial Variations in Femtosecond Field Dynamics within a Plasmonic Nanoresonator Mode

Plasmonic resonators can be designed to support spectrally well-separated discrete modes. The associated characteristic spatial patterns of intense electromagnetic hot-spots can be exploited to enhance light-matter interaction. Here, we study the local field dynamics of individual hot-spots within a nanoslit resonator by detecting characteristic changes of the photoelectron emission signal on a scale of ∼12 nm using time-resolved photoemission electron microscopy (TR-PEEM) and by excitation with the output from a 20 fs, 1 MHz noncollinear optical parametric amplifier (NOPA). Surprisingly, we detect apparent spatial variations of the Q-factor and resonance frequency that are commonly considered to be global properties for a single mode. By using the concept of quasinormal modes we explain these local differences by crosstalk of adjacent resonator modes. Our findings are important in view of time-domain studies of plasmon-mediated strong light-matter coupling at ambient conditions.

Highly Confined and Switchable Mid-Infrared Surface Phonon Polariton Resonances of Planar Circular Cavities with a Phase Change Material

Mid-infrared (MIR) photonics demands highly confined optical fields to obtain efficient interaction between long-wavelength light and nanomaterials. Surface polaritons excited on polar semiconductor and metallic material interfaces exhibit near-fields localized on subwavelength scales. However, realizing a stronger field concentration in a cavity with a high quality ( Q) factor and a small mode volume is still challenging in the MIR region. This study reports MIR field concentration of surface phonon polaritons (SPhPs) using planar circular cavities with a high Q factor of ∼150. The cavities are fabricated on a thin film of the phase change material Ge₃Sb₂Te₆ (GST) deposited on a silicon carbide (SiC) substrate. Scattering-type scanning near-field optical microscopy visualizes the near-field distribution on the samples and confirms directly that the SPhP field is strongly concentrated at the center of the centrosymmetric cavities. The smallest concentrated field size is 220 nm in diameter which corresponds to 1/50 of the wavelength of the incident light that is far below the diffraction limit. The thin GST film enhances the SPhP confinement, and it is used to switch the confinement off by tuning the cavity resonance induced by the phase change from the amorphous to the crystalline phase. This subwavelength and switchable field concentration within a high- Q polariton cavity has the potential to greatly enhance the light-matter interaction for molecular sensing and emission enhancement in MIR systems.

The microstructure of buccal cavity and alimentary canal of Siganus rivulatus: Scanning electron microscope study

The microstructure of the oral cavity and alimentary canal of herbivorous fish Siganus rivulatus collected from the Red Sea were investigated by using scanning electron microscope (SEM). The results showed that S. rivulatus has three types of teeth, tri-cusped, bi-cusped, and papilliform. A taste bud (Type I) was recorded in the oropharyngeal cavity. Characteristic styles of microridges on the cell's surface inside the buccal cavity were recorded. Also, the distribution of the mucous cells in the lining of the mouth cavity, alimentary canal was observed. Mucosal folds along the distinct parts of alimentary canal, showed characteristic pattern which was complex in the intestinal mucosa. The results concluded that there are characteristic microstructures according to feeding habitat compared with other bony fishes.

Protein Solvent Interaction: Transition of Protein-solvent Interaction Concept from Basic Research into Solvent Manipulation of Chromatography

Previously, we have reviewed in this journal (Arakawa, T., Kita, Y., Curr. Protein Pept. Sci., 15, 608-620, 2014) the interaction of arginine with proteins and various applications of this solvent additive in the area of protein formulations and downstream processes. In this special issue, we expand the concept of protein-solvent interaction into the analysis of the effects of solvent additives on various column chromatography, including mixed-mode chromatography. Earlier in our research, we have studied the interactions of such a variety of solvent additives as sugars, salts, amino acids, polymers and organic solvents with a variety of proteins, which resulted in mechanistic understanding on their protein stabilization and precipitation effects, the latter known as Hofmeister series. While such a study was then a pure academic research, rapid development of genetic engineering technologies and resultant biotechnologies made it a valuable knowledge in fully utilizing solvent additives in manipulation of protein solution, including column chromatography.

Field Evaluation of a Portable Whispering Gallery Mode Accelerometer

An accelerometer utilising the optomechanical coupling between an optical whispering gallery mode (WGM) resonance and the motion of the WGM cavity itself was prototyped and field-tested on a vehicle. We describe the assembly of this portable, battery operated sensor and the field-programmable gate array automation. Pre-trial testing using an electrodynamic shaker demonstrated linear scale-factors with <0.3% standard deviation (±6 g range where g = 9.81 ms−2), and a strong normalised cross-correlation coefficient (NCCC) of rICP/WGM=0.997 when compared with an integrated circuit piezoelectric (ICP) accelerometer. A noise density of 40 μg Hz−1/2 was obtained for frequencies of 2–7 kHz, increasing to 130 μg Hz−1/2 at 200 Hz, and 250 μg Hz−1/2 at 100 Hz. A reduction in the cross-correlation was found during the trial, rICP/WGM = 0.36, which we attribute to thermal fluctuations, mounting differences, and the noisy vehicle environment. The deployment of this hand-fabricated sensor, shown to operate and survive during ±60 g shocks, demonstrates important steps towards the development of a chip-scale device.

The Immune Mechanisms of Lung Parenchymal Damage in Tuberculosis and the Role of Host-Directed Therapy

Impaired lung function is common in people with a history of tuberculosis. Host-directed therapy added to tuberculosis treatment may reduce lung damage and result in improved lung function. An understanding of the pathogenesis of pulmonary damage in TB is fundamental to successfully predicting which interventions could be beneficial. In this review, we describe the different features of TB immunopathology that lead to impaired lung function, namely cavities, bronchiectasis, and fibrosis. We discuss the immunological processes that cause lung damage, focusing on studies performed in humans, and using chest radiograph abnormalities as a marker for pulmonary damage. We highlight the roles of matrix metalloproteinases, neutrophils, eicosanoids and cytokines, like tumor necrosis factor-α and interleukin 1β, as well as the role of HIV co-infection. Finally, we focus on various existing drugs that affect one or more of the immunological mediators of lung damage and could therefore play a role as host-directed therapy.

Prognostic factors for surgically resected non-small cell lung cancer with cavity formation

Background

Small pulmonary nodules have been detected frequently by computed tomography (CT). Lung cancers with cavity formation are also easily detected. There are a few reports focused on the cavity wall, although cancer cells exist along the cavity wall, not inside. We evaluated the impact of cavity wall thickness on prognosis and assessed the clinicopathological features in non-small cell lung cancer (NSCLC) with cavity formation.

Methods

Between 2005 and 2011, 1,313 patients underwent complete resection for NSCLC. Of these cases, we reviewed 65 patients (5.0%) diagnosed with NSCLC with cavity formation by chest CT. We classified the patients into three groups based on the maximum cavity wall thickness, namely, ≤4 mm (Group 1, 8 patients), >4 and ≤15 mm (Group 2, 33 patients), and >15 mm (Group 3, 24 patients).

Results

The number of patients with pathological whole tumor size >3 cm was 2 (25%) in Group 1, 17 (52%) in Group 2, and 23 (96%) in Group 3 (P<0.001). Cases with lymph node metastasis were 0 (0%) in Group 1, 5 (15%) in Group 2, and 10 (42%) in Group 3 (P=0.016). The 5-year overall survival (OS) rates were 100% in Group 1, 84.0% in Group 2, and 52.0% in Group 3, with significant differences between Group 1 and Group 3 (P=0.044) and between Group 2 and Group 3 (P=0.034). In univariate analysis, neither whole tumor size nor lymph node metastasis was a prognostic factor for OS (P=0.51, P=0.27). Only cavity wall thickness was a significant prognostic factor by multivariate analysis (P=0.009).

Conclusions

Maximum cavity wall thickness was an important prognostic factor in NSCLCs with cavity formation, comparable with other established prognostic factors.

Cavity-Enhanced Raman Spectroscopy for Food Chain Management

Comprehensive food chain management requires the monitoring of many parameters including temperature, humidity, and multiple gases. The latter is highly challenging because no low-cost technology for the simultaneous chemical analysis of multiple gaseous components currently exists. This contribution proposes the use of cavity enhanced Raman spectroscopy to enable online monitoring of all relevant components using a single laser source. A laboratory scale setup is presented and characterized in detail. Power enhancement of the pump light is achieved in an optical resonator with a Finesse exceeding 2500. A simulation for the light scattering behavior shows the influence of polarization on the spatial distribution of the Raman scattered light. The setup is also used to measure three relevant showcase gases to demonstrate the feasibility of the approach, including carbon dioxide, oxygen and ethene.

Exploring Protein Cavities through Rigidity Analysis

The geometry of cavities in the surfaces of proteins facilitates a variety of biochemical functions. To better understand the biochemical nature of protein cavities, the shape, size, chemical properties, and evolutionary nature of functional and nonfunctional surface cavities have been exhaustively surveyed in protein structures. The rigidity of surface cavities, however, is not immediately available as a characteristic of structure data, and is thus more difficult to examine. Using rigidity analysis for assessing and analyzing molecular rigidity, this paper performs the first survey of the relationships between cavity properties, such as size and residue content, and how they correspond to cavity rigidity. Our survey measured a variety of rigidity metrics on 120,323 cavities from 12,785 sequentially non-redundant protein chains. We used VASP-E, a volume-based algorithm for analyzing cavity geometry. Our results suggest that rigidity properties of protein cavities are dependent on cavity surface area.

Fabrications and Performance of Wireless LC Pressure Sensors through LTCC Technology

This paper presents a kind of passive wireless pressure sensor comprised of a planar spiral inductor and a cavity parallel plate capacitor fabricated through low-temperature co-fired ceramic (LTCC) technology. The LTCC material with a low Young's modulus of ~65 GPa prepared by our laboratory was used to obtain high sensitivity. A three-step lamination process was applied to construct a high quality cavity structure without using any sacrificial materials. The effects of the thickness of the sensing membranes on the sensitivity and detection range of the pressure sensors were investigated. The sensor with a 148 μm sensing membrane showed the highest sensitivity of 3.76 kHz/kPa, and the sensor with a 432 μm sensing membrane presented a high detection limit of 2660 kPa. The tunable sensitivity and detection limit of the wireless pressure sensors can meet the requirements of different scenes.

Role of halogen-halogen contacts in the crystal structures of three new solvates of the drug oxyclozanide

Halogen-halogen contacts are electrostatic in nature and exhibit directionality similar to hydrogen bonds. Oxyclozanide [systematic name: 2,3,5-trichloro-N-(3,5-dichloro-2-hydroxyphenyl)-6-hydroxybenzamide] is a drug used for the treatment of fascioliasis in domestic animals. The molecule carries five chlorine substituents and represents an ideal candidate for the study of halogen bonds in the crystal. Three new crystalline solvates of oxyclozanide, namely, oxyclozanide benzene hemisolvate, C₁₃H₆Cl₅NO₃·0.5C₆H₆, (I), oxyclozanide xylene hemisolvate, C₁₃H₆Cl₅NO₃·0.5C₈H₁₀, (II), and oxyclozanide toluene hemisolvate, C₁₃H₆Cl₅NO₃·0.5C₇H₈, (III), were structurally characterized. In this context, the crystal structure of oxyclozanide chlorobenzene hemisolvate, C₁₃H₆Cl₅NO₃·0.5C₆H₅Cl, (IV), was redetermined based on intensity data collected at 100 K. In all four solvates, the cocrystallized solvent molecules are located on crystallographic inversion centres. Solvates (I)-(IV) exhibit similar one-dimensional hydrogen-bonded chains generated by O-H...O, O-H...Cl and Cl...Cl interactions. The extension of these one-dimensional chains into two-dimensional layers is promoted by Cl...Cl and C-H...π contacts. Solvates (III) and (IV) are isostructural and differ from (I) and (II) with respect to subtle details concerning the intermolecular contacts.

IChem: A Versatile Toolkit for Detecting, Comparing, and Predicting Protein-Ligand Interactions

Structure-based ligand design requires an exact description of the topology of molecular entities under scrutiny. IChem is a software package that reflects the many contributions of our research group in this area over the last decade. It facilitates and automates many tasks (e.g., ligand/cofactor atom typing, identification of key water molecules) usually left to the modeler's choice. It therefore permits the detection of molecular interactions between two molecules in a very precise and flexible manner. Moreover, IChem enables the conversion of intricate three-dimensional (3D) molecular objects into simple representations (fingerprints, graphs) that facilitate knowledge acquisition at very high throughput. The toolkit is an ideal companion for setting up and performing many structure-based design computations.

Plasmonic Waveguide Coupled Ring Cavity for a Non-Resonant Type Refractive Index Sensor

Sensitive refractive index sensors with small footprints have been studied to allow the integration of a large number of sensors into a tiny chip for bio/chemical applications. In particular, resonant-type index sensors based on various micro/nanocavities, which use a resonant wavelength dependence on the refractive index of the analyte, have been developed. However, the spectral linewidth of the resonance, which becomes the resolution limit, is considerably large in plasmonic cavities due to the large absorption loss of metals. Therefore, there is demand for a new type of plasmonic refractive index sensor that is not limited by the linewidth of the cavity. We propose a new type of plasmonic index sensors consisting of a channel waveguide and a ring cavity. Two emissions from the ring cavity in both directions of the waveguide couple with a reflection phase difference depending on the length of a closed right arm with a reflecting boundary. Therefore, the output power dramatically and sensitively changes as a function of the refractive index of the analyte filling the waveguide.

Fluid-Structure Finite-Element Modelling and Clinical Measurement of the Wideband Acoustic Input Admittance of the Newborn Ear Canal and Middle Ear

The anatomical differences between the newborn ear and the adult one result in different input admittance responses in newborns than those in adults. Taking into account fluid-structure interactions, we have developed a finite-element model to investigate the wideband admittance responses of the ear canal and middle ear in newborns for frequencies up to 10 kHz. We have also performed admittance measurements on a group of 23 infants with ages between 14 and 28 days, for frequencies from 250 to 8000 Hz with 1/12-octave resolution. Sensitivity analyses of the model were performed to investigate the contributions of the ear canal and middle ear to the overall admittance responses, as well as the effects of the material parameters, measurement location and geometrical variability. The model was validated by comparison with our new data and with data from the literature. The model provides a quantitative understanding of the canal and middle-ear resonances around 500 and 1800 Hz, respectively, and also predicts the effects of the first resonance mode of the middle-ear cavity (around 6 kHz) as well as the first and second standing-wave modes in the ear canal (around 7.2 and 9.6 kHz, respectively), which may explain features seen in our high-frequency-resolution clinical measurements.

Multiple cavitating pulmonary nodules: rare manifestation of benign metastatic leiomyoma

Benign metastasizing leiomyoma (BML) is a rare disease of pathologically benign, but the tumor metastasizes to other organs. The most common organ involved in BML is lung. Pulmonary involvement usually manifested as multiple nodules on chest X-ray, however we experienced an interesting case of a 52-year-old premenopausal woman who presented with multiple bilateral lung cavitations and nodules on a chest X-ray without any respiratory symptoms. Chest computed-tomography identified multiple cavitary lesions of 5-12 mm in diameter and well-defined nodules of 5-10 mm in diameter in both lung fields. Transthoracic needle biopsy was performed and the resected lesion consisted of benign spindle cells was positive for estrogen receptor (ER) and progesterone receptor (PR) and was diffuse positive for actin and desmin by immunohistochemical (IHC) staining, suggesting leiomyoma. The final diagnosis was benign pulmonary metastasizing leiomyoma (BPML) and the patient underwent subcutaneous injection of a gonadotrophin releasing hormone (GnRH) agonist for 12 months, follow-up low-dose chest computed tomography (CT) scan at 15 months revealed decreased cavitations and nodular lesions. We should take into consideration the possibility of BPML when we encounter multiple cystic or cavitary lesions on chest X-ray, although the common form of BPML is nodulary lesions on imaging studies.

High-Efficiency Second-Harmonic Generation from Hybrid Light-Matter States

We report a novel approach to modify the second order nonlinear optical (NLO) susceptibility of organic nanofiber crystals by hybridization with the optical modes of microcavities in the strong coupling regime. The wavelength dependence of the SHG efficiency displays two intense peaks corresponding to the so-formed light-matter hybrid states. Our results demonstrate an enhancement of the resonant SHG efficiency of the lower polariton by 2 orders of magnitude for the collectively coupled molecules as compared to that of the same material outside the microcavity. This study is a proof of principle that opens a new direction for NLO of organic materials in subwavelength resonators.

Cavity-enhanced coherent light scattering from a quantum dot

The generation of coherent and indistinguishable single photons is a critical step for photonic quantum technologies in information processing and metrology. A promising system is the resonant optical excitation of solid-state emitters embedded in wavelength-scale three-dimensional cavities. However, the challenge here is to reject the unwanted excitation to a level below the quantum signal. We demonstrate this using coherent photon scattering from a quantum dot in a micropillar. The cavity is shown to enhance the fraction of light that is resonantly scattered toward unity, generating antibunched indistinguishable photons that are 16 times narrower than the time-bandwidth limit, even when the transition is near saturation. Finally, deterministic excitation is used to create two-photon N00N states with which we make superresolving phase measurements in a photonic circuit.

Isolated pulmonary mucormycosis presenting as cavitary lesion in an immunocompetent adult: A rare case report

Cavitary lung lesions have a specific array of differential diagnosis. Among rare causes is mucormycosis that should not be overlooked. A high index of suspicion is necessary for a correct diagnosis and aggressive management. It usually occurs in immunosupressed patients. It is a life-threatening, rapidly progressive, and angioinvasive fungal infection. We present a case of pulmonary mucormycosis presenting as a cavity in an immunocompetent middle aged male.

Confinement of Surface Plasmon Polaritons by Heterostructures of Plasmonic Crystals

Square lattice plasmonic crystals (SQ-PlCs) composed of silver pillars generate large bandgaps for surface plasmon polaritons (SPPs). SPP confinement is demonstrated using one- and two-dimensional heterostructures of SQ-PlCs comprised of cylindrical pillars with different diameters in a common square lattice. Two kinds of localized modes are observed to appear in the heterostructures by photon map imaging using cathodoluminescence (CL) technique combined with a scanning transmission electron microscopy (STEM). Angle-resolved CL spectroscopy reveals contrasting characteristics of the two localized modes in their emission distributions, indicating that they originate from the band-edge A and E modes of the matrix SQ-PlC.

Control of Light Emission by a Plasmonic Crystal Cavity

Surface plasmon-polaritons (SPPs) localized inside a plasmonic crystal (PlC) cavity are probed by STEM-CL technique to characterize the influence of the surface shape parameters on the cavity modes. The results elucidate the formation mechanism of the cavity mode in terms of the symmetry and quality factor, which provide a clear design guide for the PlC cavity to control the coupling between SPPs and photons in plasmonic devices and future integrated circuits.

Iatrogenic Damage to the Periodontium Caused by Endodontic Treatment Procedures: An Overview

The tooth, the pulp tissue within it and its supporting structures should be viewed as one biologic unit. The interrelationship of these structures influences each other during health, function and disease. The interrelationship between periodontal and endodontic diseases has aroused much speculation, confusion and controversy. The endodontium and periodontiumare closely related and disease or damage of one tissue may lead to the involvement of the other.

Outcome correlation of smear-positivity but culture-negativity during standard anti-tuberculosis treatment in Taiwan

BACKGROUND

The appearance of smear-positivity but culture-negativity (SPCN) for acid-fast bacilli among sputum specimen is frequently found in pulmonary tuberculosis (TB) patients during treatment. This study aimed to investigate clinical risk factors, impacts on treatment course, and relapse pattern associated with sputum SPCN.

METHODS

We retrospectively enrolled 800 patients with culture-proven pulmonary TB who were receiving standard treatment and follow-up at six TB-referral hospitals in Taiwan between January 2006 and December 2007. Relevant patient characteristics and chemotherapy data were analyzed for associations with incidence of SPCN. Data from patients who relapsed within 3 years after completing treatment were analyzed for associations with SPCN during treatment.

RESULTS

Of the 800 subjects, 111 (13.8%) had sputum SPCN during treatment. Three factors were found to predict the development of SPCN; namely, high initial acid-fast staining grading (OR, 3.407; 95% CI, 2.090-5.553), cavitation on chest-X ray films (OR, 2.217; 95% CI, 1.359-3.615), and smoking (OR, 1.609; 95% CI, 1.006-2.841). Patients with SPCN had longer treatment duration (rifampicin: 284 ± 91 vs. 235 ± 69 days, P <0.001; isoniazid: 289 ± 90 vs. 234 ± 69 days, P < 0.001) than those without SPCN. Finally, the rate of relapse within 3 years of completing treatment was similar for groups with/without SPCN (2.7%, 3/111 vs. 1.0%, 7/689, respectively; P = 0.15).

CONCLUSIONS

In conclusion, severity of infection was a major risk factor for SPCN during treatment; however, the relapse rate within 3 years of completing treatment was not affected by the appearance of SPCN.

Analysis of autophagy in Penicillium chrysogenum by using starvation pads in combination with fluorescence microscopy

The study of cellular quality control systems has emerged as a highly dynamic and relevant field of contemporary research. It has become clear that cells possess several lines of defense against damage to biologically relevant molecules like nucleic acids, lipids and proteins. In addition to organelle dynamics (fusion/fission/motility/inheritance) and tightly controlled protease activity, the degradation of surplus, damaged or compromised organelles by autophagy (cellular 'self-eating') has received much attention from the scientific community. The regulation of autophagy is quite complex and depends on genetic and environmental factors, many of which have so far not been elucidated. Here a novel method is presented that allows the convenient study of autophagy in the filamentous fungus Penicillium chrysogenum. It is based on growth of the fungus on so-called 'starvation pads' for stimulation of autophagy in a reproducible manner. Samples are directly assayed by microscopy and evaluated for autophagy induction / progress. The protocol presented here is not limited for use with P. chrysogenum and can be easily adapted for use in other filamentous fungi.

Risk factors for microbiologic failure among Taiwanese adults with Mycobacterium abscessus complex pulmonary disease

BACKGROUND

The Mycobacterium abscessus complex is a common cause of pulmonary nontuberculous mycobacteria infections in Taiwan. We examined the risk factors associated with treatment outcome in Taiwanese adults with pulmonary disease caused by the M. abscessus complex.

METHODS

We retrospectively reviewed the records of all patients from a southern Taiwan medical center from 2006 to 2012 who had respiratory specimens identified as M. abscessus complex and met the American Thoracic Society criteria for pulmonary disease.

RESULTS

Of the 106 included patients, females (58.5%) and nonsmokers (79.2%) predominated. The mean age of patients was 64.8 years. Sixty-three patients (59.4%) had pre-existing lung disease. Previous mycobacterial pulmonary disease (34.9%) was the most common underlying disorder. Chest radiography indicated that bronchiectasis was common (47.2%) and that cavitations were less common (14.2%). Fifty-six patients received antibiotic treatment. Clinicians were more likely to prescribe antibiotics if the initial sputum acid-fast staining was positive (p < 0.001). Treatment outcome was analyzed in 26 patients who were treated for more than 3 months; three of these patients (11.5%) had clinical failure and 18 (69.2%) experienced sputum conversion. Patients with cavitary lesions were more likely to experience microbiologic failure (p = 0.02). Nine patients had positive cultures after antibiotic treatment for > 1 year. Previous mycobacterial pulmonary disease (p = 0.011) and cavitary lesion (p = 0.034) are risk factors for persistence of M. abscessus complex.

CONCLUSION

With antimicrobial therapy, previous mycobacterial disease, and cavitary lesion are associated with microbiologic failure in Taiwanese adults with M. abscessus complex pulmonary disease.

Synergistic actions of olomoucine and bone morphogenetic protein-4 in axonal repair after acute spinal cord contusion

To determine whether olomoucine acts synergistically with bone morphogenetic protein-4 in the treatment of spinal cord injury, we established a rat model of acute spinal cord contusion by impacting the spinal cord at the T₈ vertebra. We injected a suspension of astrocytes derived from glial-restricted precursor cells exposed to bone morphogenetic protein-4 (GDAs^BMP) into the spinal cord around the site of the injury, and/or olomoucine intraperitoneally. Olomoucine effectively inhibited astrocyte proliferation and the formation of scar tissue at the injury site, but did not prevent proliferation of GDAs^BMP or inhibit their effects in reducing the spinal cord lesion cavity. Furthermore, while GDAs^BMP and olomoucine independently resulted in small improvements in locomotor function in injured rats, combined administration of both treatments had a significantly greater effect on the restoration of motor function. These data indicate that the combined use of olomoucine and GDAs^BMP creates a better environment for nerve regeneration than the use of either treatment alone, and contributes to spinal cord repair after injury.

Mycobacterium tuberculosis dysregulates MMP/TIMP balance to drive rapid cavitation and unrestrained bacterial proliferation

Active tuberculosis (TB) often presents with advanced pulmonary disease, including irreversible lung damage and cavities. Cavitary pathology contributes to antibiotic failure, transmission, morbidity and mortality. Matrix metalloproteinases (MMPs), in particular MMP-1, are implicated in TB pathogenesis. We explored the mechanisms relating MMP/TIMP imbalance to cavity formation in a modified rabbit model of cavitary TB. Our model resulted in consistent progression of consolidation to human-like cavities (100% by day 28), with resultant bacillary burdens (>10(7) CFU/g) far greater than those found in matched granulomatous tissue (10(5) CFU/g). Using a novel, breath-hold computed tomography (CT) scanning and image analysis protocol, we showed that cavities developed rapidly from areas of densely consolidated tissue. Radiological change correlated with a decrease in functional lung tissue, as estimated by changes in lung density during controlled pulmonary expansion (R(2)  = 0.6356, p < 0.0001). We demonstrated that the expression of interstitial collagenase (MMP-1) was specifically greater in cavitary compared to granulomatous lesions (p < 0.01), and that TIMP-3 significantly decreased at the cavity surface. Our findings demonstrated that an MMP-1/TIMP imbalance is associated with the progression of consolidated regions to cavities containing very high bacterial burdens. Our model provided mechanistic insight, correlating with human disease at the pathological, microbiological and molecular levels. It also provided a strategy to investigate therapeutics in the context of complex TB pathology. We used these findings to predict a MMP/TIMP balance in active TB and confirmed this in human plasma, revealing the potential of MMP/TIMP levels as key components of a diagnostic matrix aimed at distinguishing active from latent TB (PPV = 92.9%, 95% CI 66.1-99.8%, NPV = 85.6%; 95% CI 77.0-91.9%).