Huge Cavities Research Articles

Layer-by-layer self-assembly of giant polyelectrolyte microcapsules templated by microbubbles as potential hydrophilic or hydrophobic drug delivery system

Giant polyelectrolyte microcapsules (GMs) with huge cavities and extremely low wall-to-diameter ratios have superior high loading ability and controlled permeability. However, the series of problems brought by template removal seriously impede their applications in biomedicine. In this work, a combination of microbubbles (MBs) as templates and layer-by-layer (LbL) self-assembly technology was used to fabricate GMs as potential hydrophilic or hydrophobic drug delivery system by depositing poly (allylamine hydrochloride) and poly(styrene sulfonate) onto monodispersity bovine serum albumin or liposome (Lipo) MBs. CLSM and AFM images showed that the GMs have a diameter of 100.4 ± 14.2 μm and a thickness of nearly 100 nm. Due to the difficulty in loading hydrophobic molecules into the hydrophilic structure of LbL capsules, we focused on encapsulating paclitaxel (PTX) into GMs based on PTX-loaded Lipo MBs, which presented high-drug loading and notable sustained-release effects. Collectively, these GMs have tremendous potential for drug delivery.

A versatile gas-generator promoting drug release and oxygen replenishment for amplifying photodynamic-chemotherapy synergetic anti-tumor effects

Excellent efficiency of combinational therapy of chemotherapy and photodynamic therapy (PDT) highly depends on the amounts of drug and oxygen in tumor tissue. However, how to cleverly promote drug release accompanied with improving oxygen concentration remains a challenge. Herein, we proposed a gas-generator that realized a high drug loading and integrated facilitation of drug release with oxygen replenishment into a single and simple system, utilizing huge cavities and mesoporous channels of hollow mesoporous silica nanoparticles (HMSNs) for encapsulating oxygen (O2) saturated perfluoropentane (PFP) droplets, indocyanine green (ICG) and doxorubicin (DOX), biocompatible polydopamine (PDA) as the gatekeepers. Under irradiation of 808 nm laser, the thermal effect of PDA caused PFP droplets occur liquid-gas phase transition that triggered the burst release of DOX and O2, finally amplifying the synergetic effects of PDT and chemotherapy both in vitro and in vivo. The influence of PFP, GSH and laser on drug release kinetic was explored through mathematical models. Notably, the mechanism of gas-generator on accelerating drug release under irradiation based on doing volume work and enhancing diffusion coefficient was clarified by researching the relation between DOX release, PFP release and temperature change. Additionally, the way of replenishing O2 did not rely on intracellular components but timely offered abundant “fuels” for producing reactive oxygen species (ROS) when compared with traditional manners. This work provides a new research strategy for boosting drug release and opens an avenue for constructing multifunctional controlled delivery systems.

LmIntegrinβ-PS is required for wing morphogenesis and development in Locusta migratoria.

Wings are an important flight organ of insects and their morphogenesis depends on a series of cell-to-cell and cell-to-extracellular matrix interactions. Integrin as a transmembrane protein receptor mediates cell-to-cell adhesion, cell-to-extracellular matrix interactions and signal transduction. In the present study, we characterized an integrin gene that encodes integrinβ-PS protein in Locusta migratoria. LmIntegrinβ-PS is highly expressed in the wing pads and the middle stages of 5th instar nymphs. Immunohistochemical analysis revealed that the LmIntegrinβ-PS protein was localized at the cell base of the two layers of wings. After suppression of LmIntegrinβ-PS by RNA interference, the wing pads or wings were unable to form normally, with a blister wing appearance during nymph to nymph transition and nymph to adult transition. We further found that the dorsal and ventral epidermis of the wings after dsLmIntegrinβ-PS injection were improperly connected and formed huge cavities revealed by hematoxylin and eosin staining. Furthermore, the morphology and structure of the wing cuticle was significantly disturbed which affected the stable arrangement and attachments of the wing epidermis. Moreover, the expression of related cell adhesion genes was significantly decreased in LmIntegrinβ-PS-suppressed L. migratoria, suggesting that LmIntegrinβ-PS is required for the morphogenesis and development of wings during molting by stabilizing cell adhesion and maintaining the cytoskeleton of these cells.

An X-ray chimney extending hundreds of parsecs above and below the Galactic Centre.

Evidence has mounted in recent decades that outflows of matter and energy from the central few parsecs of our Galaxy have shaped the observed structure of the Milky Way on a variety of larger scales1. On scales of 15 parsecs, the Galactic Centre has bipolar lobes that can be seen in both the X-ray and radio parts of the spectrum2,3, indicating broadly collimated outflows from the centre, directed perpendicular to the Galactic plane. On larger scales, approaching the size of the Galaxy itself, γ-ray observations have revealed the so-called 'Fermi bubble' features4, implying that our Galactic Centre has had a period of active energy release leading to the production of relativistic particles that now populate huge cavities on both sides of the Galactic plane. The X-ray maps from the ROSAT all-sky survey show that the edges of these cavities close to the Galactic plane are bright in X-rays4-6. At intermediate scales (about 150 parsecs), radio astronomers have observed the Galactic Centre lobe, an apparent bubble of emission seen only at positive Galactic latitudes7,8, but again indicative of energy injection from near the Galactic Centre. Here we report prominent X-ray structures on these intermediate scales (hundreds of parsecs) above and below the plane, which appear to connect the Galactic Centre region to the Fermi bubbles. We propose that these structures, which we term the Galactic Centre 'chimneys', constitute exhaust channels through which energy and mass, injected by a quasi-continuous train of episodic events at the Galactic Centre, are transported from the central few parsecs to the base of the Fermi bubbles4.

Invasive pulmonary aspergillosis secondary to microwave ablation: a multicenter retrospective study

Purpose: Invasive pulmonary aspergillosis (IPA) is a life-threatening complication of microwave ablation (MWA) during the treatment of primary or metastatic lung tumors. The purpose of this study was to investigate the clinical, radiological and demographic characteristics and treatment responses of patients with IPA after MWA.Materials and methods: From January 2011 to January 2016, all patients who were treated by MWA of their lung tumors from six health institutions were enrolled in this study. Patients with IPA secondary to MWA were identified and retrospectively evaluated for predisposing factors, clinical treatment, and outcome.Results: The incidence of IPA secondary to lung MWA was 1.44% (23/1596). Of the 23 patients who developed IPA, six died as a consequence, resulting in a high mortality rate of 26.1%. Using computed tomography (CT), pulmonary cavitation was the most common finding and occurred in 87.0% (20/23) of the patients. Sudden massive hemoptysis was responsible for one-third of the deaths (2/6). Most patients (22/23) received voriconazole as an initial treatment, and six patients with huge cavities underwent intracavitary lavage. Finally, 17 patients (73.9%) achieved treatment success.Conclusions: Lung MWA may be an additional host risk factor for IPA, particularly in elderly patients with underlying diseases and in patients who have recently undergone chemotherapy. Early and accurate diagnosis of IPA after MWA is critical for patient prognosis. Voriconazole should be given as the first-line treatment as early as possible. Bronchial artery embolization or intracavitary lavage may be required in some patients.

Seed-mediated phase-selective growth of Cu2GeS3 hollow nanoparticles with huge cavities

Although significant progress has been achieved in the synthesis of hollow nanoparticles (NPs), research on copper-based multinary chalcogenide (CMC) semiconductor NPs with hollow structures is still less developed.

A versatile stimulus-responsive metal-organic framework for size/morphology tunable hollow mesoporous silica and pH-triggered drug delivery.

Metal-organic frameworks (MOFs) have spurred tremendous research interest in the fields of nanoscience and nanotechnology. However, exploring their biomedical applications is still a daunting challenge. In this work, we employed an acid-degradable MOF, zeolitic imidazolate framework-8 (ZIF-8), both as a self-sacrificial template to synthesize uniform size/morphology-controllable hollow mesoporous silica materials (HMSNs) and as a mesopore blocker for fabricating a pH-responsive HMSN-based drug delivery system. Starting from the ZIF-8 template, a layer of mesoporous silica is coated on ZIF-8 and subsequently the template was self-degraded under acidic conditions to obtain HMSNs. A series of monodisperse HMSNs ranging from ca. 80 nm to ca. 3000 nm with morphologies that give rare examples of cubic and dodecahedral morphologies has been prepared. It is demonstrated that the as-made HMSNs possess well-defined mesopores, huge cavities and good biocompatibility, which make them favourable for drug delivery. So, ZIF-8 was then grafted onto the HMSN to block the pore orifice for pH-responsive intracellular anticancer drug release. The results indicated that the ZIF-8-coated HMSN with encapsulated doxorubicin hydrochloride (DOX) was an efficient drug delivery vehicle in cancer therapy using pH-responsive release. This strategy sheds new light on the application of MOF materials and provides great potential for biomedical applications.

Ice-shelf basal morphology from an upward-looking multibeam system deployed from an autonomous underwater vehicle

The huge cavities beneath floating Antarctic ice shelves have only been explored recently by autonomous underwater vehicles (AUVs). Oceanic waters above the in situ freezing point melt those faces of marine-terminating glaciers and ice shelves with which they come into contact. This, in turn, impacts the dynamics of ice sheets as the reduction in buttressing allows the ice to flow faster into the ocean, increasing their contribution to eustatic sea-level rise (Shepherd et al. 2012). Pine Island Glacier (PIG) in West Antarctica (Fig. 1a, d) is an example, and has been accelerating and thinning over past decades, and still appears to be in retreat. This is driven by unpinning from a seabed ridge and exposure to high ocean temperatures of up to 1°C at the grounding line (Jenkins et al. 2010) that are subject to climatically forced variability (Dutrieux et al. 2014 a ). Fig. 1. ( a ) Surface elevation of Pine Island Glacier ice shelf (colour) (Dutrieux et al. 2013) overlays a Moderate Resolution Imaging Spectroradiometer image obtained on 28 December 2008. Thick black line shows the boundary between floating and grounded ice …

Ih Symmetrical (4,6)‐Fullerenes and Their Local Ring Aromaticity: A First Principle Study

As the natural extension of carbon fullerene, a series of Ih symmetrical (4,6)‐fullerenes were constructed and investigated using first principle methods. These Ih (4,6)‐fullerenes consist of many four‐ and six‐membered rings and are classified into two types: (1) those with isolated four‐ and six‐membered rings and (2) those with connected four‐ and/or six‐membered rings. Though these (4,6)‐fullerenes are less stable than Ih C60 and C240 (5,6)‐fullerene, it is possible to synthesize them from their elemental unit, antikekulene, which was nearly synthesized experimentally. Though the (4,6)‐fullerenes are mainly spherical and antiaromatic compounds, the local aromatic indexes indicate that all of the planar π‐conjugated rings have local aromaticity in fullerenes, which provides reasonable delocalization, which is consistent with our chemical intuition. Because of the huge cavities and suitable pore sizes present in the (4,6)‐fullerenes, they can be taken as potential nanocontainers for the storage of small molecules.

Local ISM 3D distribution and soft X-ray background

3D maps of the ISM can be used to locate not only IS clouds, but also IS bubbles between the clouds that are blown by stellar winds and supernovae. We compare our 3D maps of the IS dust to the ROSAT diffuse X-ray background maps. In the Plane, there is a good correspondence between the locations and extents of the mapped nearby cavities and the 0.25 keV background emission distribution, showing that most of these nearby cavities contribute to this soft X-ray emission. Assuming a constant dust to gas ratio and homogeneous 1MK hot gas filling the cavities, we modeled in a simple way the 0.25 keV surface brightness along the Galactic plane as seen from the Sun, taking into account the absorption by the mapped clouds. The data-model comparison favors the existence of hot gas in the Local Bubble (LB). The average mean pressure in the local cavities is found to be on the order of about 10,000 cm-3K, in agreement with previous studies. The model overestimates the emission from the huge cavities in the 3rd quadrant. Using CaII absorption data, we show that the dust to CaII ratio is very small in this region, implying the presence of a large quantity of lower temperature (non-X-ray emitting) ionized gas, explaining at least part of the discrepancy. In the meridian plane, the two main brightness enhancements coincide well with the chimneys connecting the LB to the halo. No nearby cavity is found towards the bright North Polar Spur (NPS) at high latitude. We searched in the maps for the source regions of the 0.75 keV enhancements in the 4th and 1st quadrants. Tunnels and cavities are found to coincide with the main bright areas, however no tunnel nor cavity is found to match the low-latitude, brightest part of the NPS. In addition, the comparison between the maps and published spectra do not favor the nearby cavities located within about 200pc as potential source regions for the NPS.

A highly permeable and selective zeolitic imidazolate framework ZIF-95 membrane for H2/CO2 separation

Making use of the preferred adsorption affinity and capacity to CO(2) as well as the highly porous structure with huge cavities of 2.4 nm, a highly permeable and selective ZIF-95 molecular sieve membrane was developed for the separation of H(2) from CO(2).

Core/Shell Structured Hollow Mesoporous Nanocapsules: A Potential Platform for Simultaneous Cell Imaging and Anticancer Drug Delivery

A potential platform for simultaneous anticancer drug delivery and MRI cell imaging has been demonstrated by uniform hollow inorganic core/shell structured multifunctional mesoporous nanocapsules, which are composed of functional inorganic (Fe(3)O(4), Au, etc.) nanocrystals as cores, a thin mesoporous silica shell, and a huge cavity in between. The synthetic strategy for the creation of huge cavities between functional core and mesoporous silica shell is based on a structural difference based selective etching method, by which solid silica middle layer of Fe(2)O(3)@SiO(2)@mSiO(2) (or Au@SiO(2)@mSiO(2)) composite nanostructures was selectively etched away while the mesoporous silica shell could be kept relatively intact. The excellent biocompatibility of obtained multifunctional nanocapsules (Fe(3)O(4)@mSiO(2)) was demonstrated by very low cytotoxicity against various cell lines, low hemolyticity against human blood red cells and no significant coagulation effect against blood plasma. The cancer cell uptake and intracellular location of the nanocapsules were observed by confocal laser scanning microscopy and bio-TEM. Importantly, the prepared multifunctional inorganic mesoporous nanocapsules show both high loading capacity (20%) and efficiency (up to 100%) for doxorubicin simultaneously because of the formation of the cavity, enhanced surface area/pore volume and the electrostatic interaction between DOX molecules and mesoporous silica surface. Besides, the capability of Fe(3)O(4)@mSiO(2) nanocapsules as contrast agents of MRI was demonstrated both in vitro and in vivo, indicating the simultaneous imaging and therapeutic multifunctionalities of the composite nanocapsules. Moreover, the concept of multifunctional inorganic nanocapsules was extended to design and prepare Gd-Si-DTPA grafted Au@mSiO(2) nanocapsules for nanomedical applications, further demonstrating the generality of this strategy for the preparation of various multifunctional mesoporous nanocapsules.

Two-Dimensional Organic Brick-Wall Layers as Hosts for the Inclusion and Study of Aromatics Ensembles: Acid−Pyridine and Acid−Carbonyl Synthons for Multicomponent Materials

The compound trimesic acid (H3TMA) with 2,6-bis(4-pyridylmethylene)cyclohexanone (1) was shown to form two-/three-/four-component cocrystals or salts depending on the reaction conditions. Crystals of salt were obtained when crystallized H3TMA and 1 from MeOH alone, whereas the crystals of neutral components were obtained when crystallized from MeOH and phenol mixture. Both the structures (salt and cocrystal) exhibited huge cavities which are occupied by the self-interpenetration of the networks. This self-interpenetration of the networks found to be eschewed in favor of guest inclusion when the crystallization reactions are conducted in the presence of suitable aromatic guest molecules such as biphenyl, naphthalene, anthracene, phenanthrene, pyrene, triphenylene, and 1,4-hydroquinone. The crystal structures of cocrystals contain hydrogen-bonded layers with huge cavities, the self-interpenetrated layers have a honeycomb geometry with the cavity dimensions of 23 × 42 A2 and the guest included layers have a ...

Tissue Stabilizer Reverse Mounting in Minimally Invasive Direct Coronary Artery Bypass, a Simple Tool in Difficult Times

The simple reverse mounting of an Octopus arm over a rib retractor can give more arm length by up to 5 cm inside the chest cavity which could prove to be very useful in patients with huge chest cavities, i.e. chronic obstructive pulmonary disease, high body mass index, allowing more flexibility and better maneuverability of the stabilizer arm during MIDCAB.

Corrosion behaviour of sensitized AISI-type 316L stainless steel in molten carbonate fuel cell in cathode-gas environment

Corrosion of the cell components is a major problem in the development of the molten carbonate fuel cell (MCFC). This study describes the effect of sensitization on the corrosion characteristics of AISI-type 316L stainless steel in a 62/38 lithium–potassium carbonate eutectic melt in the cathode-gas environment. After solution treatment at 1200°C for 4 h followed by sensitization treatment at 650°C for predetermined time, the corrosion behaviour of the sensitized sample is analyzed electrochemically by a potentiodynamic method. The sensitized sample displays behaviour which is typical of active–passive transition. Increasing the time of the sensitization treatment causes the corrosion potential to shift in the cathodic direction. In addition, the passive film becomes more unstable and supports a high passive current, i.e., the substrate is more susceptible to intergranular corrosion (IGC). Morphological observation of samples immersed in a carbonate melt reveal a change in corrosion mechanism from initial IGC to localized corrosion. Huge cavities develop from grooves after 200 h of immersion in a carbonate melt. A combination of a Cr-depleted region due to sensitization and decreasing oxygen concentration from top to bottom of the oxide layer, is considered to be the main reason for the change in corrosion morphology.

Oriented macroporous polyacrylamide gels.

Macroporous gels with huge cavities and partition walls result from controlled microsyneresis during gelation. In this report we show that the microsyneresis process can be further controlled: it is possible to orient the partition walls of macropores by the use of an electric field throughout polymerization. Our oriented macroporous polyacrylamide gels offer a specific structure: a set of parallel channels of about 2 microm inner diameter, with polyacrylamide walls including acidic groups linked to the aggregated matter.

A basic study of the interstitial laser prostatectomy using pulsed holmium: yttrium-aluminum-garnet (Ho:YAG) laser

To develop a new procedure for laser prostatectomy through a biopsy needle, we evaluated the efficacy of interstitial laser irradiation with a pulsed Ho:YAG laser (lambda: 2.1 microns) in the normal canine prostate. Pathological studies were performed up to 6 months after interstitial laser irradiation in 26 mongrel dogs (15.4 +/- 2.6 kg). Two dogs underwent the identical procedures without irradiation as controls (control group). Prostate glands of the other 24 dogs were irradiated interstitially with a Ho:YAG laser through a silica glass fiber (400 microns phi). In one prostate, each lobe was irradiated with 500 J/cm2 or 150 J/cm2 in energy density (fluence). Four prostates were irradiated with 150-175 J/cm2 in fluence (low-fluence group). Nineteen prostates were irradiated with 500-600 J/cm2 in fluence (high-fluence group). Prostates glands were excised immediately, 1 month, 2 months, 3 months, or 6 months after irradiation and examined histologically. To investigate the influence of interstitial irradiation with a Ho:YAG laser on smooth muscle and/or on the adrenergic activity of the prostate, we also measured changes in intraluminal pressure of the prostatic urethra upon administration of epinephrine (10 micrograms/kg) in six dogs before and after irradiation. We developed a novel three-membrane balloon catheter with an open end for measuring this pressure change. Specimens harvested immediately in control and low-fluence groups showed slight hemorrhage in areas surrounding the punctured or irradiated site, but the surrounding smooth muscles or small vessels were not destroyed. In the high-fluence group, smooth muscles and small vessels approximately 1 mm thick that surrounded the ablated hole were destroyed, but the thickness of the thermal coagulation layer was only approximately 0.2 mm. These findings suggested that damage to the small vessels and smooth muscle may have been caused by laser-induced stress waves rather than by a thermal effect. In the control and low-fluence groups, prostatic volume remained unchanged 1 month after puncture or low-fluence irradiation. In the high-fluence group, huge cavities were created in the laser-irradiated prostate gland 1 or 2 months after irradiation and prostatic volume was reduced maximally by 60%. In the high-fluence group, the cavities collapsed and prostatic volume was reduced by up to 50% at 6 months post-procedure. The prostatic urethra expanded following the reduction in volume. The maximal intraluminal change in pressure of the prostatic urethra decreased significantly after laser irradiation (p < 0.05). Results indicate that interstitial irradiation of the prostate with a Ho:YAG laser with high-fluence may relieve the anatomical and functional obstruction of the prostatic urethra in benign prostatic hyperplasia.

前立腺肥大症に対するHo: YAGレーザー組織内照射による治療の基礎的検討

To develop a new transperineal laser prostatectomy through a biopsy needle, we evaluated the efficacy of pulsed Ho: YAG laser irradiation for the canine prostate. The Ho: YAG laser may induce stress-wave to destroy the small vessels in the prostate. Seventeen mongrel dogs were used. After a lower midline abdominal incision, the prostate was punctured with a 18G biopsy needle in parallel to the urethra. Two prostates were punctured without the irradiation as a control. One of the 15 treated prostates was removed immediately after high fluence irradiation (500J/cm2) in left lobe and low (150J/cm2) in right lobe. In 12 of 15 dogs, each lobe of the prostate was irradiated with high fluence. In 2 of 15 dogs, each lobe of the prostate was irradiated with low fluence. The treated prostates were removed immediately, 1 week, 1 month and 2 months after the irradiation. The high fluence irradiation resulted in the sufficient volume reduction (40%) and the huge cavities were created I month later. The low fluence irradiation showed only the inflammatory reaction. The histological examination showed that the hemorrhage and subsequent histological changes may be caused by the laser induced stress-wave rather than by thermal effect. Our results suggest that transperineal irradiation with pulsed Ho: YAG laser can be useful in the treatment of prostatic obstruction.

Optic Nerve Colobomas of Autosomal-Dominant Heredity

Fifteen members of a family had congenital colobomas of the optic nerves, all of which were bilateral. The bolobomas appeared as enlargement of the physiologic cup with severely affected eyes having huge cavities in the site of the disc. A variable amount of glial tissue was present within the colobomas. Either macular or extramacular serous detachment or sequelae were present in 21 of the 30 affected eyes, and often led to total blindness. Radioisotope cisternography in one patient failed to implicate cerebrospinal fluid as the source of the subretinal fluid. The disorder is apparently inherited as an autosomal dominant.