A surgical alternative of fusiform penetrating keratoplasty for the management of severe infectious keratitis

AIM:To describe the surgical procedure of fusiform penetrating keratoplasty(FPK)using multiple trephines of different sizes for treating patients with severe infectious keratitis.METHODS:Fourteen eyes underwent FPK,and 15 eyes received conventional penetrating keratoplasty(PK)were included in the study.The best-corrected visual acuity(BCVA),refractive outcomes,endothelial cell density,and postoperative complications were recorded.RESULTS:The FPK group was followed for an average of 15.3±2.1mo,whereas the PK group was followed for 16.1±1.9mo.The corneal ulcers were elliptical-shaped in all 14 eyes in the FPK group.The mean BCVA(logMAR,0.26±0.13)showed no statistically significant differences from that in the PK group(logMAR,0.21±0.12,P>0.05)at 1y after surgery.But the mean curvature,mean astigmatism,and mean spherical equivalent in the FPK group were lower than those in the PK group(P<0.05).Peripheral anterior synechia was observed in one patient in the FPK group,whereas 6 patients in the PK group.Suture loosening and neovascularization were observed in 4 and 5 eyes in the PK group,respectively.No graft immune rejection or elevation of intraocular pressure was observed in the two groups.CONCLUSION:For patients with elliptical-shaped corneas or corneal ulcers,FPK can avoid disrupting of corneal limbus,reduce the risk of postoperative complications,and can result in satisfactory visual quality.

Late corneal ectasia after penetrating and deep anterior lamellar keratoplasty for keratoconus

AIM:To investigate tomographic features of late corneal ectasia after keratoplasty for keratoconus and compare penetrating keratoplasty(PK)and deep anterior lamellar keratoplasty(DALK)in terms of incidence,time of onset and risk factors of corneal ectasia.METHODS:Sixty eyes with PK and 30 eyes with DALK operated between 1999 and 2021 were analyzed.Final Pentacam scans were evaluated together with vision and previous topographies.Main outcome measures were vision,K values,apparent thinning on graft-host cornea and the difference between opposing quadrants in the thinnest point measurements.Anterior segment optic coherence tomography was performed for further evaluation.RESULTS:Mean follow-up was 127.2mo(24–282mo)in PK,and 64.3mo(24–144mo)in DALK.K max was higher in DALK(60.6 vs 56.7 D,P=0.012).Inferior recipient was thinner(595.9μm)in PK than DALK(662.2μm,P=0.021),due to longer follow-up.Overall corneal ectasia rate was 20.0% within 24y.Ectasia rate was the same(6.7%)in DALK 2/30 and in PK 4/60 in 10y and 13.3%in 12y(4/30 and 8/60,respectively).It increased to 23.3%(14/60)in PK over 24y.While ectasia was not seen before 7y in PK,it could be seen in DALK starting from the 5^(th) year.The intervals between keratoplasty and ectasia were 144.5mo in PK and 99mo in DALK.Inferior recipient was significantly thinner in 18 eyes with ectasia(502.7μm)compared to 76 non-ectasia(649.1μm,P=0.000).Inferior graft was thinner(561.0 vs 620.4μm,P=0.006),K max(63.3 vs 56.5 D,P=0.000),and anterior elevation was higher in ectasia(89.1 vs 48.6μm,P=0.002).Accelerated crosslinking was performed on 5 eyes.CONCLUSION:Inferior-superior recipient and inferior graft thinning on tomography,with high K max and anterior elevation emerge as the most reliable criteria for the diagnosis of late ectasia.The incidence of corneal ectasia increases with the time.

Enhancing the vertical resolution of lunar penetrating radar data using predictive deconvolution

The Yutu-2 rover onboard the Chang’E-4 mission performed the first lunar penetrating radar detection on the farside of the Moon.The high-frequency channel presented us with many unprecedented details of the subsurface structures within a depth of approximately 50 m.However,it was still difficult to identify finer layers from the cluttered reflections and scattering waves.We applied deconvolution to improve the vertical resolution of the radar profile by extending the limited bandwidth associated with the emissive radar pulse.To overcome the challenges arising from the mixed-phase wavelets and the problematic amplification of noise,we performed predictive deconvolution to remove the minimum-phase components from the Chang’E-4 dataset,followed by a comprehensive phase rotation to rectify phase anomalies in the radar image.Subsequently,we implemented irreversible migration filtering to mitigate the noise and diminutive clutter echoes amplified by deconvolution.The processed data showed evident enhancement of the vertical resolution with a widened bandwidth in the frequency domain and better signal clarity in the time domain,providing us with more undisputed details of subsurface structures near the Chang’E-4 landing site.

Silicone oil migrating into the conjunctival space and orbit after surgery for an eye-penetrating injury:A case report

BACKGROUND We report a case of eye-penetrating injury in which a massive silicone oil migration into the patient’s subconjunctival space and orbit occurred after vitrectomy.CASE SUMMARY A 30-year-old male patient sought medical attention at Ganzhou People’s Hospital after experiencing pain and vision loss in his left eye due to a nail wound on December 9,2023.Diagnosis of penetrating injury caused by magnetic foreign body retention in the left eye and hospitalization for treatment.On December 9,2023,pars plana vitrectomy was performed on the left eye for intraocular foreign body removal,abnormal crystal extraction,retinal photocoagulation.Owing to the discovery of retinal detachment at the posterior pole during surgery,silicone oil was injected to fill the vitreous body,following which upper conjunctival bubble-like swelling was observed.Postoperative orbital computed tomography(CT)review indicated migration of silicone oil to the subconjunctival space and orbit through a self-permeable outlet.On December 18,2023,the patient sought treatment at the First Affiliated Hospital of Nanchang University,China.The patient presented with a pronounced foreign body sensation following left eye surgery.On December 20,2023,the foreign body was removed from the left eye frame and an intraocular examination was conducted.The posterior scleral tear had closed,leading to termination of the surgical procedure following supplementary laser treatment around the tear.The patient reported a significant reduction in ocular surface symptoms just one day after surgery.Furthermore,a notable decrease in the migration of silicone oil was observed in orbital CT scans.CONCLUSION The timing of silicone oil injection for an eye-penetrating injury should be carefully evaluated to avoid the possibility of silicone oil migration.

Steel bar penetrating cervical spinal canal without neurological injury:A case report

BACKGROUND We report a rare case of cervical spinal canal penetrating trauma and review the relevant literatures.CASE SUMMARY A 58-year-old male patient was admitted to the emergency department with a steel bar penetrating the neck,without signs of neurological deficit.Computed tomography(CT)demonstrated that the steel bar had penetrated the cervical spinal canal at the C6–7 level,causing C6 and C7 vertebral body fracture,C6 left lamina fracture,left facet joint fracture,and penetration of the cervical spinal cord.The steel bar was successfully removed through an open surgical procedure by a multidisciplinary team.During the surgery,we found that the cervical vertebra,cervical spinal canal and cervical spinal cord were all severely injured.Postoperative CT demonstrated severe penetration of the cervical spinal canal but the patient returned to a fully functional level without any neurological deficits.CONCLUSION Even with a serious cervical spinal canal penetrating trauma,the patient could resume normal work and life after appropriate treatment.

Management of Penetrating Cranioencephalic Trauma Caused by Sharp Metal Objects—Therapeutic and Evolutionary Aspects: 12 Cases at the Renaissance University Hospital in N’Djamena

Introduction: Cranioencephalic trauma caused by bladed weapons is rare, and that caused by sharp objects is exceptional. The aim of our study was to describe the clinical, therapeutic and evolutionary aspects. Materials and method: This was a descriptive and analytical study over a 48-month period at CHU la Renaissance from January 1, 2018 to December 31, 2021, concerning patients admitted for penetrating cranioencephalic trauma by pointed object. Results: Twelve cases, all male, of penetrating cranioencephalic sharp-force trauma were identified. The mean age was 34 ± 7 years, with extremes of 11 and 60 years. Farmers and herders accounted for 31% and 25% of cases respectively. The average admission time was 47 hours. Brawls were the circumstances of occurrence in 81.2% of cases. Knives (33%), arrows (25%) and iron bars (16.6%) were the objects used. Altered consciousness was present in 43.8% of cases, and focal deficit in 50%. Scannographic lesions were fracture and/or embarrhment (12 cases), intra-parenchymal haematomas (6 cases) and presence of object in place (4 cases). Surgery was performed in 11 patients. Postoperative outcome was favorable in 9 patients. After 12 months, 2 patients were declared unfit. Conclusion: Penetrating head injuries caused by sharp objects are common in Chad. Urgent surgery can prevent disabling after-effects.

Delayed Pseudoaneurysms of Vertebral Artery Post Penetrating Trauma: A Case Report

Objective: Vascular injuries usually present immediately after the penetration, but the delayed onset of vascular symptoms caused by vessel dissection or aneurysm after a traumatic event is extremely rare. Vertebral artery injury is a low-frequency but high-mortality injury. We aim to report evidence of delayed onset of vascular symptoms following penetrating trauma in the neck. Materials and Methods: A case report. Results: A 19-year-old boy was referred to our hospital and complained of a mass in the right part of his neck (right mandibular angle). He gave a history of penetrating trauma to his neck 2 months ago. The mass was expanding during these 2 months and doesn’t respond to antibiotic therapy. In the examination, 3 × 3 cm, firm, nonmobile, and without tenderness and pain mass was palpated in the second level of his neck. Doctors ordered a Doppler sonography in the hospital where a yin-yang pattern was reported. A 36 × 43 × 40 mm heterogeneous, solid, and hypodense area close to C1-C2-C3 with vascular flow was discovered in the right submandibular area after computed tomography (CT)-angiography. The patient was referred to an interventional neurologist for angiography and due to the lack of flow at the distal of the V3 segment, he decided to sacrifice this artery by two coils. Conclusion: Penetrating neck injuries are usually asymptomatic, but these injuries are often accompanied by hemorrhage, neurological symptoms, dysphagia, odynophagia, and windpipe. Penetrating lesions of the vertebral artery are rare and very difficult to diagnose. Also, these lesions are challenging for surgeons due to complex anatomy and difficult surgical exposure. So, endovascular treatment was used to treat the patient.

Ballistic performance of spherical fragments penetrating PCrNi3MoV target plates

PCrNi3MoV steel is a medium-carbon,low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation resistance.To study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres,tungsten spheres of various diameters(5 mm,8 mm,and 10 mm)were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm,9 mm,and 14 mm.The penetration performance of the spheres was analyzed for different velocities,and the ultimate penetration velocity of the plate was obtained.It was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear failure.Using the dimensional analysis method,a relationship between the bulge height of the steel plate and the fragment velocity,an equation for the ultimate penetration velocity,and a relationship between the target penetration energy and the fragment velocity were obtained.Then,a projectile-target action index was proposed to describe the process of tungsten spheres with different velocities impacting target plates.The results suggested that under the same thickness of the target plate,a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter fragment.The equations obtained through dimensional analysis predicted values that agreed well with experimental values,indicating that these equations can be applied to engineering applications.

Acute penetrating injury of the spinal cord by a wooden spike with delayed surgery:a case report

Rarely,penetrating injuries to the spinal cord result from wooden objects,creating unique challenges to mitigate neurological injury and high rates of infection and foreign body reactions.We report a man who sustained a penetrating cervical spinal cord injury from a sharpened stick.While initially tetraparetic,he rapidly recovered function.The risks of neurological deterioration during surgical removal made the patient reluctant to consent to surgery despite the impalement of the spinal cord.A repeat MRI on day 3 showed an extension of edema indicating progressive inflammation.On the 7~(th)day after injury,fever and paresthesias occurred with a large increase in serum inflammatory indicators,and the patient agreed to undergo surgical removal of the wooden object.We discuss the management nuances related to wood,the longitudinal evolution of MRI findings,infection risk,surgical risk mitigation and technique,an inflammatory marker profile,long-term recovery,and the surprisingly minimal neurological deficits associated with low-velocity midline spinal cord injuries.The patient had an excellent clinical outcome.The main lessons are that a wooden penetrating central nervous system injury has a high risk for infection,and that surgical removal from the spinal cord should be performed soon after injury and under direct visualization.

Frontal penetrating arrow injury:A case report

BACKGROUND Penetrating arrow injuries of the head and neck are exceedingly rare in pediatric patients.This pathology has high morbidity and mortality because of the presence of vital organs,the airway,and large vessels.Therefore,the treatment and removal of an arrow is a challenge that requires multidisciplinary management.CASE SUMMARY A 13-year-old boy was brought to the emergency room after an arrow injury to the frontal region.The arrowhead was lodged in the oropharynx.Imaging studies showed a lesion of the paranasal sinuses without compromising vital structures.The arrow was successfully removed by retrograde nasoendoscopy without complications,and the patient was discharged.CONCLUSION Although rare,maxillofacial arrow injuries have high morbidity and mortality and require multidisciplinary management to preserve function and aesthetics.

Correlation of Ground Penetrating Radar Data with Geotechnical Prospect Profiles: Reduto Case Study, Belém-PA, Brazil

The study presented in this manuscript aimed to relate the sedimentary strata imaged by the ground penetrating radar(GPR)method through numerical modeling with the mapping of sedimentary strata acquired through geotechnical surveys.The study aimed to expose how obtaining subsoil information through noninvasive/destructive electromagnetic waves is beneficial,as they are reliable and less costly than drilling holes beyond what is necessary to have a subsurface mapping.In this sense,physical-geological modeling was carried out.The information on the type of sediments,acquired through simple recognition surveys carried out in the city of Belém-PA,helped to create a model of a sedimentary package with its respective intrinsic physical properties.The result shows that the GPR recovered with good vertical and horizontal resolution at the beginning and end of the layers of the sedimentary package studied,proving to be very effective for locating geotechnical sounding points and safely reducing costs.

Resistance Factor of Caisson-Tip with Internal Fillet for Suction Caissons Penetrating into Clay

This paper presents failure mechanisms of the soil at the caisson-tip with fillet during suction-assisted penetration of suction caissons in undrained clay.Theoretical solutions of resistance factor N_c of the caisson-tip are obtained in terms of the caisson-tip geometry ratio of the flat section of the caisson-tip to the caisson wall thickness m/t and adhesion factorsα_i along inside of caisson wall andα_b at the base of the caisson-tip.It is indicated that the factor N_c increases with the increase of m/t,α_i and a_b.The resistance factors N_c for the rough base(α_b=1)are larger by 0.57than that for the smooth base(α_b=0).Besides,the factors N_c of caisson-tip with flat base(m=t)are larger by 1.14 than that with full internal fillet(m=0).The required suction to penetrate suction caissons with various fillets is obtained in terms of the force equilibrium in vertical direction.The finite element limit analysis and centrifuge model test results are used to verify the rationality of the presented failure mechanisms and theoretical predictions.

Effect of corneal graft diameter on therapeutic penetrating keratoplasty for fungal keratitis

AIM: To evaluate the effect of corneal graft diameter on therapeutic penetrating keratoplasty(PKP) for fungal keratitis. METHODS: A total of 116 patients (116 eyes) suffered from fungal keratitis underwent PKP at the Affiliated Hospital of Medical College Qingdao University from May 2006 to May 2010. They were divided into two groups according to the corneal graft diameter. 64 eyes' corneal graft diameter was 8.00mm or larger and 52 eyes' graft diameter was smaller than 8.00mm. The follow-up time was 2 years. The postoperative visual acuity and complications were documented and compared. RESULTS: Sixty-two (96.88%) eyes and fifty (96.15%) eyes preserved eyeballs respectively in two groups. There was no statistical difference in postoperative visual acuity (P = 0.961), corneal graft dear rate (P=0.132) or the incidence of recurred fungal infection (P=0.770) between two groups. But there was a higher incidence of graft rejection (P=0.020) and secondary glaucoma (P=0.039) in group with corneal graft diameter 8.00mm or larger. CONCLUSION: PKP is an effective treatment approach for fungal keratitis. There is a higher incidence of complications in large-diameter PKP for fungal keratitis.Effective, preventive and therapeutic measures can improve the prognosis.

Developments of mucus penetrating nanoparticles

Mucus can effectively protect the exposed mucosal surfaces due to its adhesive and viscoelastic properties.Most foreign particulates are efficiently trapped in mucus layers via steric obstruction and adhesion.Trapped particles are typically removed from the mucosal tissue within seconds to a few hours depending on their location sites.This article focuses on describing the tenacious mucus barrier properties,the strategies to investigate the interaction of nanoparticles with the mucus as well as the novel developments of mucus penetrating nanoparticles.

Feature Extraction and Classification of Echo Signal of Ground Penetrating Radar

Automatic feature extraction and classification algorithm of echo signal of ground penetrating radar is presented. Dyadic wavelet transform and the average energy of the wavelet coefficients are applied in this paper to decompose and extract feature of the echo signal. Then, the extracted feature vector is fed up to a feed forward muhi layer perceptron classifier. Experimental results based on the measured GPR, echo signals obtained from the Mei shan railway are presented.

Modified Method for Estimating Organic Carbon Density in Discontinuous Karst Soil Using Ground-Penetrating Radar and Geostatistics

The conventional method which assumes the soil distribution is continuous was unsuitable for estimating soil organic carbon density(SOCD) in Karst areas because of its discontinuous soil distribution. The accurate estimation of SOCD in Karst areas is essential for carbon sequestration assessment in China. In this study, a modified method,which considers the vertical proportion of soil area in the profile when calculating the SOCD, was developed to estimate the SOCD in a typical Karst peak-cluster depression area in southwest China. In the modified method, ground-penetrating radar(GPR) technology was used to detect the distribution and thickness of soil. The accuracy of the method was confirmed through comparison with the data obtained using a validation method, in which the soil thickness was measured by excavation. In comparison with the conventional method and average-soil-depth method,the SOCD estimated using the GPR method showed the minimum relative error with respect to that obtained using the validation method. At a regional scale, the average SOCDs at depths of 0-20 cm and 0-100 cm, which were interpolated by ordinary kriging,were 1.49(ranging from 0.03-5.65) and 2.26(0.09-11.60) kgm-2based on GPR method in our study area(covering 393.6 hm2), respectively. Therefore, the modified method can be applied on the accurate estimation of SOCD in discontinuous soil areas such as Karst regions.

Root imaging from ground penetrating radar data by CPSO-OMP compressed sensing

As the amount of data produced by ground penetrating radar （GPR） for roots is large, the transmission and the storage of data consumes great resources. To alleviate this problem, we propose here a root imaging algorithm using chaotic particle swarm optimal （CPSO） compressed sensing based on GPR data according to the sparsity of root space. Radar data are decomposed, observed, measured and represented in sparse manner, so roots image can be reconstructed with limited data. Firstly, radar signal measurement and sparse representation are implemented, and the solution space is established by wavelet basis and Gauss random matrix; secondly, the matching function is considered as the fitness function, and the best fitness value is found by a PSO algorithm; then, a chaotic search was used to obtain the global optimal operator; finally, the root image is reconstructed by the optimal operators. A-scan data, B-scan data, and complex data from American GSSI GPR is used, respectively, in the experimental test. For B-scan data, the computation time was reduced 60 % and PSNR was improved 5.539 dB; for actual root data imaging, the reconstruction PSNR was 26.300 dB, and total computation time was only 67.210 s. The CPSO-OMP algorithm overcomes the problem of local optimum trapping and comprehensively enhances the precision during reconstruction.

Overcoming the cellular barriers and beyond: Recent progress on cell penetrating peptide modified nanomedicine in combating physiological and pathological barriers

The complex physiological and pathological conditions form barriers against efficient drug delivery.Cell penetrating peptides(CPPs),a class of short peptides which translocate drugs across cell membranes with various mechanisms,provide feasible solutions for efficient delivery of biologically active agents to circumvent biological barriers.After years of development,the function of CPPs is beyond cell penetrating.Multifunctional CPPs with bioactivity or active targeting capacity have been designed and successfully utilized in delivery of various cargoes against tumor,myocardial ischemia,ocular posterior segment disorders,etc.In this review,we summarize recent progress in CPP-functionalized nano-drug delivery systems to overcome the physiological and pathological barriers for the applications in cardiology,ophtalmology,mucus,neurology and cancer,etc.We also highlight the prospect of clinical translation of CPP-functionalized drug delivery systems in these areas.

Penetrating behavior of eutectic liquid during Al/Cu contact reactive brazing

The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the depth direction. Meanwhile, dissolution of solid Al and Cu into the eutectic liquid promotes the eutectic reaction and the continuously formed eutectic liquid leads to the reactive penetrating.