Hard Tip Research Articles

Converting Short-Acting Insulin into Thermo-Stable Longer-Acting Insulin Using Multi-Layer Detachable Microneedles

The detachable dissolving microneedles (DDMNs) feature an array of needles capable of being separated from the base sheet during administration. Here they were fabricated to address delivery efficiency and storage stability of insulin. The constructed insulin-DDMN is multi-layered, with 1) a hard tip cover layer; 2) a layer of regular short-acting insulin (RI) mixed with hyaluronic acid (HA) and sorbitol (Sor) which occupies the taper tip region of the needles; 3) a barrier layer situated above the RI layer; and 4) a fast-dissolving layer connecting the barrier layer to the base sheet. RI entrapped in DDMNs exhibited enhanced thermal stability; it could be stored at 40 °C for 35 days without losing significant biological activity. Differential scanning calorimetric analysis revealed that the HA-Sor matrix could improve the denaturation temperature of the RI from lower than room temperature to 186 °C. Tests in ex vivo porcine skin demonstrated RI delivery efficiency of 91±1.59 %. Experiments with diabetic rats revealed sustained release of RI, i.e., when compared to subcutaneous injection with the same RI dose, RI-DDMNs produced slower absorption of insulin into blood circulation, delayed onset of hypoglycemic effect, longer serum insulin half-life, and longer hypoglycemic duration.

Safety and feasibility of a novel recanalization technique using guidewire puncture under cholangioscopy for complete biliary stricture after liver transplantation

Cholangioscopy is reportedly useful for selective guidewire placement across difficult biliary strictures, but few methods are available for complete stricture of biliary anastomosis. This study aimed to propose a guidewire puncture technique to recanalize totally obstructed anastomosis and discuss its safety and feasibility. From January 2015 to December 2021, a total of 11 patients with complete biliary anastomotic stricture after liver transplantation were enrolled. These patients underwent peroral single operator cholangioscopy (SpyGlass), whereas two failed cases on SpyGlass finally underwent percutaneous transhepatic cholangioscopy (PTCS). The steps of the recanalization technique were as follows: the stricture was viewed carefully to detect the closure point (CP) of the scar endoscopically, then the CP was targeted by the hard tip of the guidewire and broke through under guidance of the cholangioscope and fluoroscope. Complete occlusions were confirmed by SpyGlass in all cases. A total of 13 hard-tip guidewire punctures were performed under cholangioscopy, and ten punctures were successful (technical success rate, 76.9% [10/13]). After recanalization of the occluded anastomosis, plastic stent or metallic stent was deployed in three and seven patients, respectively. No procedure-related complications occurred during or after the cholangioscopy-assisted guidewire puncture. After a mean follow-up of 12 months, stents had been removed in five patients. The other six patients were still receiving stent treatment. This study demonstrated that the guidewire puncture technique under cholangioscopy is safe and feasible for complete stricture of biliary anastomosis, and the success rate is satisfactory.

RECANNULATION OF COMPLETELY OCCLUDED BRONCHUS INTERMEDIUS WITH A DIODE LASER

RECANNULATION OF COMPLETELY OCCLUDED BRONCHUS INTERMEDIUS WITH A DIODE LASER

The study on the morphological changes of oropharynx in patients with complete unilateral cleft lip and palate after palatopharyngeal closure.

Cleft lip and palate can be treated as one of the most common craniofacial congenital malformations in humans. Such disease influences tens of millions of patients all over the world. Cleft lip and palate deformity affects many important physiological functions, including breathing, swallowing, speech, chewing, and aesthetics. This work focuses on investigating the morphology and airway volume of oropharynx patients with unilateral complete cleft lip and palate after palatopharyngeal closure. In addition, this work evaluated the similarities and differences between patients with cleft lip and palate and those without such an issue. The employed data, selected from the Department of Stomatology of Xuzhou First People's Hospital, are based on the conical beam CT images. The study sample was divided into two groups: the selected experimental group, who confronted the cleft lip, cleft palate, and velopharyngeal closure surgery, and the selected control group, who are healthy children at the corresponding age. The parameters, including the airway volume, the airway volume of velopharyngeal and oropharyngeal segments, the minimum cross-sectional area of the pharynx, the horizontal plane airway area of the hard palate and soft one, the horizontal airway area of the hyoid bone, and the vertical distance between the hard palate and soft palate, can be measured by Dolphin. These parameters were analyzed with a statistical approach. The analysis of the above-mentioned parameters reveals that the airway volume, the minimum cross-sectional area of the pharynx, the horizontal cross-sectional area of the hyoid, and the distance between the hard palate and soft palate tip in patients with complete unilateral cleft lip and palate show significant differences between the experimental group and the control group. Meanwhile, other parameters, including the horizontal cross-sectional area of the airway in the horizontal plane of the hard palate and the horizontal plane of the soft palate, did not show noticeable differences in the two groups. The patients, who confronted the unilateral complete cleft lip and palate, can improve with the velopharyngeal closure surgery. Furthermore, the length and vertical distance of the soft palate and the volume of each segment of the airway exhibit differences between the experimental group and the control group.

Upgrading the mechanical properties of marine structural steel by enhancement of acicular ferrite formation

AbstractThis work reports the results of an investigation of the effect of magnesium addition on microstructure evolution, acicular ferrite formation together with the change in the mechanical properties of micro‐alloyed steel plates. The investigated steel is subjected to high heat input (4.5 kJ mm−1) simulating the thermal cycle of heat affected zones, conducted by induction heating in a computer controlled weld thermal cycle simulator. Both magnesium and magnesium free steel samples have carbon and aluminum contents of 0.08 wt.% and 0.009 wt.%, respectively, are investigated. The change in microstructure, hardness and crack tip opening displacement fracture toughness properties due to magnesium addition is evaluated, and compared with the other steel having the same chemical compositions but without Magnesium. The fracture toughness tests reveal the increase of magnesium steel‘s crack tip opening displacement values. In contrast, the hardness measuring presents the decrease of its hardness due to the decrease of martensite volume fraction and reduction in ferrite grain size. Optical and transmission electron microscopy observations detect some microstructural morphology that can affect the mechanical properties of such steels. Hence, the improved toughness of magnesium containing steel are attributed to both the generation of acicular ferrite nucleated within the matrix, refined microstructure and the bainite dominated microstructure in steel.

Application of nanoindentation creep tests to characterize viscoelasticity behavior of deep Longmaxi shales

The development of deep shale gas reservoirs has become economically and commercially viable through novel horizontal well completion and multistage hydraulic fracturing technologies in recent years. In the Sichuan Basin, the deep Longmaxi shale is a major target formation that has attracted increasing interest. Shale is generally characterized as a sedimentary rock with fine grains, high clay, and organic content, low permeability and porosity, and high heterogeneity and anisotropy. Geomechanical characterization of these organic-rich rocks usually includes an estimation of the elastic modulus, strength properties, hysteresis behavior, and creep deformation. Understanding and characterizing the viscoelastic behaviors of shale is essential because they affect the elastic and fracture properties of rock and cause a series of drilling problems related to the wellbore stability, such as borehole shrinkage, pipe sticking, and casing collapse. The viscoelastic behavior of specimens retrieved from a deep well in the Sichuan Basin was examined using nanoindentation creep tests. Nanoindentation is a technique based on a hard tip, which is pressed into the surface of a sample. The advantage of this test is the use of a small sample volume, such as drilling cuttings or fragments, which are obtained easily during drilling. The results indicated that the creep modulus parallel to bedding and normal to bedding is similar, while the creep modulus of drilling cuttings is the lowest. A linear relationship was both observed between the creep modulus and hardness, Young’s modulus for deep Longmaxi shale. The Burgers creep model showed good agreement with the experimental data. The creep behavior of Longmaxi shale exhibited anisotropy, and the effect of drilling fluids could aggravate the creep displacement. These results have elucidated the creep properties in engineering problems of shale gas formation, drilling, and stimulation.

Metrological provision of measurement using NanoScan-3D microscopenanothercomer

A review of methods and instrumentation for the study of tribological and mechanical properties of the surface. It is established that the most common methods for studying these properties in the micro and nano-ranges are contact methods based on the interaction of the hard tip with the material under study. In scanning probe microscopy, a bimorph piezoceramic probe with a diamond tip is the main element of the measurement modules used for nanoindentation and sclerometry to comprehensively study the tribological and mechanical properties of the surface. The original design of the sensor allows to implement more than ten measuring techniques on one device. The operation of these devices in the semi-contact scanning probe-microscopic mode allows to obtain images of the surface relief and a map of the distribution of elastic properties. The indentation mode allows to measure hardness and modulus of elasticity, to estimate elastic
 recovery of material after indentation. The method allows to determine the abrasion resistance and hardness of the material, adhesion and thickness of thin coatings.

Scratch hardness at a small scale: Experimental methods and correlation to nanoindentation hardness

Nanoindentation and scratch experiments probe the hardness by leaving a permanent imprint on the material’s surface. The scratch hardness, however, is less used due to its unclear relation to the nanoindentation hardness and discrepancies in the evaluation methods. We investigate which scratch hardness evaluation methods lead to consistent results and for which materials and load-ranges the contact area can be estimated by the Hertz solution or by the nanoindentation hardness. Finally, we address the relation of nanoindentation and scratch hardness. Secondary influences on the scratch hardness (tip size, scratch depth and elliptical shape) are addressed. To evaluate the general applicability of the findings, we study 5 materials with significantly different deformation behavior: aluminum, copper, soda-lime glass, cementite, and silicon.

M-Shaped Auricular Cartilage as Modified Septal Extension Graft: A Study by Three-Dimensional Anthropometric Analysis in Asian Rhinoplasty.

The septal extension graft is one of the most commonly used grafts in Asian tip plasty techniques. However, the septal extension graft usually induces a hard and immobile nasal tip. The purpose of this study was to evaluate the esthetic outcomes of the modified septal extension graft with M-shaped auricular cartilage by three-dimensional anthropometric analysis. A total of 36 patients received augmentation rhinoplasty with M-shaped auricular cartilage as septal extension graft combined with silicone implant. Thirteen measurement items were evaluated using three-dimensional anthropometric techniques, and the preoperative and postoperative results were compared. The majority of patients (91.7%) were satisfied with the postoperative nasal shape. No infection, gross absorption, graft exposure, implant exposure, or implant migration was observed. Compared with the preoperative value, the nasal length, nasal height, nasal depth, nasion height, columella width, nasolabial angle, nasofrontal angle, and nasal depth-nasal width index significantly increased. The nasal width, nasal tip width, and nasal index significantly decreased. We performed tip plasty with the M-shaped auricular cartilage as modified septal extension graft, achieving a soft and mobile tip with satisfying tip projection in most patients. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Experience With Autologous Nasal Septum Cartilage Combined With Conchal Cartilage in Nasal Tip Reconstruction.

There has been an increase in use of autologous costal cartilage for nasal tip shaping material. However, there are deficiencies in using this plastic material, such as a hard nasal tip, poor nasal tip elasticity and mobility postoperatively, and some nasal tip skin thinning that allows the shape of the cartilage grafts to be felt on the surface of the nasal tip skin. To address these problems, we have combined autologous nasal septum cartilage and conchal cartilage as nasal tip graft materials, which achieve a natural shape and realistic touch postoperatively. From January 2017 to September 2019, a total of 47 patients with nasal septal cartilage combined with conchal cartilage transplantation for nasal tip plasty were screened for a retrospective study. They were followed up and evaluated for 6 to 25 months postoperatively. The operation was performed through an incision in the nose. During the operation, a piece of septal cartilage was cut to make a columella strut. Using one side of the cavitas conchae and cymba conchae cartilage as the graft material, 2 long strips of cartilage were excised for the septum extension graft, and a piece of cap cartilage was transplanted to the top of the nasal tip cartilage scaffold. The time between the operation and follow-up was greater than 6 months, with the range of follow-up and evaluation being from 6 to 25 months. Forty-six patients were satisfied with the shape of the nose. One patient complained that the nasal tip was round and large after 1 month postoperatively, but after 6 months, he was satisfied with the shape of the nasal tip after daily use of a nasal clip. In one male case, the implant was removed more than 7 months postoperatively because of hematoma and infection secondary to nasal trauma. There were 2 cases of nasal tip numbness, both of which recovered spontaneously after 12 months. After the operation, the shape of the nasal tip was round, no cartilage contour was seen on the surface, no collapse of upper nasal tip, no obvious deviation of the nasal dorsum and columella, and no deformation and displacement of the nasal tip cartilage scaffold. At the 6-month follow-up visit, each patient palpated the nasal tip for evaluation. Most patients felt their nose felt realistic and that they had good nasal tip motion. Only 1 patient felt that the nasal tip and the nasal dorsum were moving together when the tip of the nose was being pushed. Nasal septum cartilage and conchal cartilage can be combined as a graft material for reconstruction of the nasal tip. This technique uses different characteristics of each of the 2 cartilages to achieve a more realistic and esthetic outcome.

Mechanical properties of organic-rich shales based on nanoindentation: A case study of deep shale gas reservoirs in Zigong area, Sichuan Basin

The deep shale gas in the Zigong area of the Sichuan Basin has a wide distribution and has good prospects for exploration, which has become an important replacement area for shale gas exploration and development. In this area, the burial depth of Longmaxi Formation Shale is generally >3500 m. One of the most challenging tasks in the development of this type of reservoir is the accurate prediction of the mechanical properties of organic-rich shale. The application of the mechanical properties of shale is important to the success in multiple aspects of drilling, hydraulic fracturing, and production. Methods such as unconfined/triaxial compression tests with the use of core plugs and logging data interpretation are commonly used to obtain mechanical properties. However, these methods have their own limitations. Thus, to address the difficulty in the measurement of the mechanical properties of shale, the advanced nanoindentation test is introduced and used. Nanoindentation is a technique based on a hard tip, which is pressed into the surface of a sample. The advantage of this test is the use of a sample with a small volume, such as drill cuttings or fragments, which are easily obtained during drilling. The mechanical properties at the nanoscale level, including the hardness, Young’s modulus, and fracture toughness, are measured in the nanoindentation. Moreover, this technique can be used to evaluate the creep behavior of shale. In this study, grid nanoindentation is used to investigate the mechanical properties of drill cutting samples from the Longmaxi Formation Shale in Zigong area, Sichuan Basin. Subsequently, these mechanical parameters are used to evaluate the heterogeneous properties of shale at the nanoscale level. The results can help in analyzing the correlation between rock mechanical properties and shale constituents. This suggests that the nanoindentation test is a useful approach of estimating the elastic and mechanical properties of shale in situations where conventional rock mechanics test data cannot be measured.

Tumor retractor: a simple and novel instrument for brain tumor surgery

BackgroundIt is important to secure a surgical space during brain tumor surgery. One of the commonly used methods is to retract the brain. We hypothesized that the tumor can be retracted and that the normal brain tissue retraction can be minimized during surgery, and thus, the degree of collateral damage caused by brain retraction would be reduced.MethodsThe tumor retractor had a 90°, hard, and sharp tip for fixation of the tumor. The distal part of the retractor has a malleable and thin blade structure. By adjusting the angle of the distal malleable part of the tumor retractor, the operator can make the retracting angle additionally. Retractors with thin blade can be used in a conventional self-retraction system. To pull and hold the tumor constantly, the tumor retractor is held by a self-retraction system. The surgical technique using a tumor retractor is as follows: The first step is to fix the retractor to the tumor. The second step is to pull the retractor in the operator’s desired direction by applying force. After the tumor is pulled by adjusting the degree of force and angle, the surgical arm should be held in place to maintain the tumor retracted state.ResultsThe tumor retractor was used to minimize the brain retraction, pulling the tumor in the opposite direction from the surrounding brain tissue. In clinical cases, we can apply the tumor retractor with good surgical outcomes.ConclusionsA tumor retractor can be used to pull a tumor and minimize the brain retraction.

Static and modal analysis of diaphragm spring used in micro depth sensing indenting Machine

Abstract Indentation is perhaps the most commonly applied means of testing the mechanical properties of materials. In a traditional indentation test (macro or micro indentation), a hard tip whose mechanical properties are known (frequently made of a very hard material like diamond) is pressed into a sample whose properties are unknown. The load placed on the indenter tip is increased as the tip penetrates further into the specimen and soon reaches a user-defined value. This paper presents the analysis and testing of diaphragm spring used in the Micro Depth Sensing Indenting Machine developed at Indian Institute of Science, Bangalore. Deflection of the spring are found out for various loads using ANSYS and results are validated through physical testing. Modal analysis of spring is carried out to find the possibility of resonance.

Mechanical analysis of femoral stress-riser fractures

BackgroundA stress-riser fracture develops when stress in an object is higher than that in the surrounding material. The aim of this retrospective study was to evaluate all consecutive femoral stress-riser fractures during a period of >10 years and to verify high-risk factors by using mechanical analysis. MethodsForty clinical fractures caused by local stress concentration in the femoral cortical bone were included. Risk factors were analyzed, and Sawbones models were used to verify their effect. One hundred thirty-six models were divided into 6 groups to simulate clinical cases of stress-riser fractures. A dynamic test instrument was used to simulate weight-bearing on the femoral head by continuous application of increasing axial force; the lever arm was applied at a constant speed of 0.1 mm/s until a fracture developed. ResultsFemale gender (57.5%), subtrochanteric area (40%), osteoporosis (40%), and technical or surgical errors (50%) were risk factors for stress-riser fractures in clinical analysis. Cortical perforation, tiny cracks, sharp corners, and changes in hardness were the main risk factors in biomechanical aspects. Mechanical analysis identified that these factors contributed to stress-riser fractures (P = 0.000), especially cortical perforations and sharp corners. ConclusionA cortical perforation (screw hole), tiny crack (fracture line), sharp corner (bone cut), and change in hardness (tip of an implant or cement) can act as a stress riser. Screw holes are the most common and critical contributor to femoral stress-riser fractures.

Fabrication of nanostructure in inner-surface of AISI 304 stainless steel pipe with surface plastic deformation

In the present investigation, a pipe inner-surface grinding (PISG) technique was developed to fabricate nanostructure in the inner-surface of an austenitic 304 stainless steel pipe. PISG was performed by high speed shearing with hard sphere tips, leading to gradient distribution of strain, strain rate and strain gradient along depth. Nano-austenite with an average boundary spacing of 20 nm was generated, followed by deformation microstructure characterized by shear bands, multi- and uni-directional twins and planar dislocation arrays. Deformation induced grain refinement of austenitic 304 stainless steel with low stacking fault energy (SFE) covering 4–5 order’s magnitude of length scales toward nanometer regime was unified.

High magnetization Co-GdOx superparamagnetic granular films as magnetic coating materials for high-sensitivity alternating magnetic force microscopy tip

The Coy(GdOx)1−y, CoyAg1−y, (Fe70Co30)y(AlOx)1−y superparamagnetic (SP) granular films were fabricated by magnetron co-sputtering technique and compared for their magnetic properties. The effect of the different matrix (GdOx, Ag, AlOx) is investigated for refining and separating magnetic particles in non-magnetic matrix by calculating the magnetic volume fraction (y), and the results indicate that the GdOx matrix can more effectively refine and separate magnetic particles. The Co0.44(GdOx)0.56 SP film with the maximum Co volume fraction (y = 0.44) approaches the highest magnetization of 608 emu/cm3 at 20 kOe, and initial susceptibility (1.74 × 10−5 H/m) as compared with Co-Ag, Fe70Co30-AlOx films and some systems of other researchers at room temperature (RT). The magnetic particle size and size distribution in these SP films is calculated by fitting with Langevin function and the results of calculation are consistent with the high-resolution transmission electron microscopy (HRTEM) results. To further confirm the SP behavior, the blocking temperature of the Co0.44(GdOx)0.56 film with the maximum Co volume fraction is measured as ∼145 K, which is below RT. Finally, the Co0.33(GdOx)0.67 thin film having a linear magnetization curve is used for the fabrication of the SP tip and further used for the A-MFM measurement on the bulk Sr-Ferrite (SrF) magnet. The fabricated Co0.33(GdOx)0.67 SP tip along with A-MFM shows an excellent result as compared to the state of art FePt hard magnetic tip using conventional MFM, and it can directly detect the intensity and identify the polarity of the stray field originating from a bulk Sr-Ferrite (SrF) permanent magnet without topography crosstalk in ambient atmosphere.

Using Patient Reported Outcomes Measures to Promote Integrated Care.

Introduction:Patient reported outcome measures (PROMs) have been introduced as standardised outcomes, but have not been implemented widely for disease targeted pathways of care, nor for geriatric patients who prefer functional performance and quality of life.Discussion:We describe innovative multipurpose implementation of PROMs as evidenced by two best practices of PROMs application in geriatric and physiotherapy practice. We show that PROMs can show meaningful outcomes in older subjects’ patient journeys, which can at the same time serve individuals and groups of both patients and professionals.Key lesson:PROMs can deliver generic outcomes relevant for older patients, may improve patient-physician relationship, quality of care and prediction of future outcomes in geriatric care, if they are valid, reliable and responsive, but still short and simple. A precondition to make the hard tip from research to practice is that PROMs are carefully positioned in the clinical encounters and in electronic health records.

Investigation on Impact Hammer Testing with Different Types of Hammer Tip for Welded Thin Plate

Modal testing using impact hammer had been used extensively in various industries to analyze the dynamic properties of the structure. Impact testing become famous due to their advantages for instances; fast, compatible for measurements in the field and relatively inexpensive. Even though these methods are fast and convenient, many important consideration should be take note during the measurement in order to get an accurate result. For this paper, hammer tip selection become the research issue. The thin sheet plate with different materials (Aluminum alloy; AA7075 & AA6061) joined by friction stir welding (FSW) will be used as a specimen. Four types of hammer tip used in this study; hard, medium, soft and super soft tip. The effect of hammer tip towards the shape of coherence and frequency response function for ranging between 0 to 1000 Hz will be discussed further. From this experiment, it was found that medium tip chosen as the most compatible tip for thin plate joined by FSW.

High resolution magnetic field energy imaging of the magnetic recording head by A-MFM with Co-GdOx super-paramagnetic tip

In this letter, the concept of a high-resolution magnetic field energy imaging technique is demonstrated by a high susceptibility superparamagnetic Co-GdOx magnetic force microscopy (MFM) tip for a perpendicular magnetic recording head with alternating magnetic force microscopy (A-MFM). The distribution of the magnetic energy gradient from the perpendicular recording head is imaged by the Co-GdOx superparamagnetic tip and compared with magnetic field imaging by the FePt-MgO hard magnetic tip. The Fourier analysis of the A-MFM amplitude images revealed enhancement in a spatial resolution of 13 nm by the Co-GdOx superparamagnetic tip as compared to 17 nm by the state-of-the-art FePt-MgO hard magnetic tip. The magnetic dipolar nature and short range force character of magnetic energy imaging by the Co-GdOx superparamagnetic tip showed high performance, confirmed by the tip transfer function analysis as compared to the monopole type FePt-MgO hard magnetic tip. The proposed technique opens an opportunity for the development of advanced high-resolution magnetic energy based imaging methods and development of the high-resolution MFM tips.

Evolutionary origins of pectin methylesterase genes associated with novel aspects of angiosperm pollen tube walls

The early evolution of angiosperms was marked by a number of innovations of the reproductive cycle including an accelerated fertilization process involving faster transport of sperm to the egg via a pollen tube. Fast pollen tube growth rates in angiosperms are accompanied by a hard shank-soft tip pollen tube morphology. A critical actor in that morphology is the wall-embedded enzyme pectin methylesterase (PME), which in type II PMEs is accompanied by a co-transcribed inhibitor, PMEI. PMEs convert the esterified pectic tip wall to a stiffer state in the subapical flank by pectin de-esterification. It is hypothesized that rapid and precise targeting of PME activity was gained with the origin of type II genes, which are derived and have only expanded since the origin of vascular plants. Pollen-active PMEs have yet to be reported in early-divergent angiosperms or gymnosperms. Gene expression studies in Nymphaea odorata found transcripts from four type II VGD1-like and 16 type I AtPPME1-like homologs that were more abundant in pollen and pollen tubes than in vegetative tissues. The near full-length coding sequence of one type II PME (NoPMEII-1) included at least one PMEI domain. The identification of possible VGD1 homologs in an early-diverging angiosperm suggests that the refined control of PMEs that mediate de-esterification of pectins near pollen tube tips is a conserved feature across angiosperms. The recruitment of type II PMEs into a pollen tube elongation role in angiosperms may represent a key evolutionary step in the development of faster growing pollen tubes.