Sharp Scratch Research Articles

Healable Supracolloidal Nanocomposite Water-Borne Coatings.

Water-borne coatings often contain nanofillers to enhance their mechanical or optical properties. The aggregation of these fillers may, however, lead to undesired effects such as brittle and opaque coatings, reducing their performance and lifetime. By controlling the distribution and structural arrangement of the nanofillers in the coatings and inserting reversible chemical bonds, both the elasticity and strength of the coatings may be effectively improved, while healing properties, via the reversible chemistry, extend the coating's lifetime. Aqueous dispersions of polymer-core/silica-corona supracolloidal particles were used to prepare water-borne coatings. Polymer and silica nanoparticles were prefunctionalized with thiol/disulfide groups during the supracolloid assembly. Disulfide bridges were further established between a cross-linker and the supracolloids during drying and coating formation. The supracolloidal nanocomposite coatings were submitted to intentional (physical) damages, i.e., blunt and sharp surface scratches or cut through into two pieces, and subsequently UV irradiated to induce the recovery of the damage(s). The viscoelasticity and healing properties of the coatings were examined by dynamic, static, and surface mechanical analyses. The nanocomposite coatings showed a great extent of interfacial restoration of cut damage and surface scratches. The healing properties are strongly related to the coating's viscoelasticity and interfacial (re)activation of the disulfide bridges. Nanocomposite coatings with silica concentrations below their critical volume fraction show higher in situ healing efficiency, as compared to coatings with higher silica concentration. This work provides insights into the control of nanofillers distribution in water-borne coatings and strategies to increase the coating lifetime via mechanical damage recovery.

Endurance Strength and Residual Life Assessment of T23 Steel after 96000 Hours of High Temperature and High Pressure Service

The macroscopic morphology, oxide layer characteristics, rupture strength and residual life of T23 steel after 96000 hours of service at high temperature and high pressure were analyzed. The results show that T23 steel pipe has good macroscopic appearance, without obvious abnormal features such as cracks, folds, rolling breaks, double skin, scabs, delaminations and sharp scratches. The chemical composition of different pipe sections conforms to the standard, and the structure is mainly bainite, with uniform distribution and no obvious coarse phase. There is an obvious interface between the metal substrate and the internal oxide layer, and there is an obvious wavy line at the interface. The oxide layer is relatively dense and continuous. The tensile properties at room temperature and high temperature are good. At room temperature, the yield strength exceeds 420MPa, the tensile strength exceeds 540MPa, and the elongation exceeds 19%. After 96000 hours of use, the remaining creep life of T23 split platen superheater submitted for inspection is 84000 hours, and the remaining creep life of T23 rear platen superheater submitted for inspection is 40000 hours.

UJI EFEKTIVITAS SALEP EKSTRAK ETANOL DAUN BUNGA KERTAS (BOUGAINVILLEA GLABRA) TERHADAP LUKA EKSISI PADA TIKUS JANTAN PEMBANDING POVIDONE IODINE SALEP

The wound is a physical injury that results in tears and damage to skin tissue. One type of wound is excision wound, excision wound is of the a wound that is caused by cutting tissue by sharp object scratches. The main goal in wound management is to achieve rapid healing with optimal function and good results. That can be achieved by preventing further infection and trauma with the availability of an environment that can optimize the healing of the wound. One plant that has the potential to heal wounds is the paper petal plant. The purpose of thes study is to find out the effectiveness of giving paper petal extract to the healing of excision wounds in male rats. The study conducted in the Laboratory Health Institute of the Deli Husada Deli Tua. The extracts formulated into ointment preparations with concentrations of 10%, 15%, and 20% then conducted evaluation of ointment preparations, namely organoleptic tests, homogeneity tests, ph tests, visicosity tests, hedonic tests and spread power tests. The results of organoleptic tests and irritant tests of paper petal ethanol extract ointment preparations, all concentrations were declared good while in the most preferred hedonic test was a concentration of 10%. From the results of the spread test is a concentration of 15% with a static test value on the 21st day which is 6.3000 where this value is equal to the value of povidone iodine, while in the pH test on the 21st day the concentration that sees the best statistic test value is 10% concentration with a value of 6.4467 which is close to the value of povidone iodine which is 7.3133. The results of the study is each treatment group experienced a decrease in the diameter of the cut wound. Of the 5 treatment groups, the best reduction in the diameter of the cut wound was the positive control group (povidone iodine) and the 20% concentration where the statistic test value on the 15th day was 0.0000 where this value was equal to the value of povidone iodine.

Implications of nocebo in anaesthesia care.

Nocebo refers to non-pharmacological adverse effects of an intervention. Well-intended procedural warnings frequently function as a nocebo. Both nocebo and placebo are integral to the generation of 'real' treatment effects and their associated 'real' side-effects. They are induced or exacerbated by: context; negative expectancy; and negative conditioning surrounding treatment. Since the late 1990s, the neuroscience literature has repeatedly demonstrated that the nocebo effect is mediated by discrete neurobiological mechanisms and specific physiological modulations. Although no single biological mechanism has been found to explain the nocebo effect, nocebo hyperalgesia is thought to initiate from the dorsal lateral prefrontal cortex subsequently triggering the brain's descending pain modulatory system and other pain regulation pathways. Functional magnetic resonance imaging shows that expectation of increased pain is accompanied by increased neural activity in the hippocampus and midcingulate cortex which is not observed when analgesia is expected. Functional magnetic resonance imaging studies have shown that the anterior cingulate cortex is pivotal in the perception of affective pain evoked by nocebo words. Research has also explored neurotransmitters which mediate the nocebo effect. The neuropeptide cholecystokinin appears to play a key role in the modulation of pain by nocebo. Hyperalgesia generated by nocebo also increases the activity of the hypothalamic-pituitary-adrenal axis as indicated by increases in plasma cortisol. The avoidance or mitigation of nocebo needs to be recognised as a core clinical skill in optimising anaesthesia care. Embracing the evidence around nocebo will allow for phrases such as 'bee sting' and 'sharp scratch' to be thought of as clumsy verbal relics of the past. Anaesthesia as a profession has always prided itself on practicing evidence-based medicine, yet for decades anaesthetists and other healthcare staff have communicated in ways counter to the evidence. The premise of every interaction should be 'primum non nocere' (first, do no harm). Whether the context is research or clinical anaesthesia practice, the nocebo can be ignored no longer.

Sharp Scratch: Podcasting the topics that medical school won’t teach you

I launched Sharp Scratch with The BMJ’s multimedia team in the spring of 2019, during my year running all things student at the world’s fourth leading medical journal. It’s a podcast where medical students, newly qualified doctors, and expert guests meet in a studio to talk about the things we need to know to be good doctors but that we may not learn at medical school. I’ve since returned to medical school and joined a new year group, where I often find myself in a circle of strangers. Many times in the last 12 months, the professionalism strand of my medical degree has put me in a circle with students I have met once or twice to discuss personal stories and to reflect. Many of the stories are familiar. The student with mental health problems shadowing an intimidating doctor on placement who feels unable to disclose their needs. The delirious or psychotic patient who inappropriately comments on a student’s appearance. The student who overhears a joke about a patient and feels a line has been crossed. And a general anxiety about a future career where we will have to respond well in situations even more complex than these. When I’m in a circle of reflecting students, I don’t always say what I’m thinking. But I’m usually thinking about an episode of Sharp Scratch.

Dress codes and skydiving: this year on Sharp Scratch.

Dress codes and skydiving: this year on Sharp Scratch.

Helen Salisbury: How will we run flu clinics in a pandemic?

In previous years, the queue for our flu vaccine clinic has been in place well before we open the doors. Patients pile into the waiting room, register with the reception staff, and roll up their sleeves in anticipation. There’s jolly banter between neighbours and occasional harrumphing if people think they’ve been kept waiting too long. Doctors and nurses try not to be drawn into too much conversation before giving the injection, preceded by the traditional warning, “Sharp scratch” (although, as it really isn’t a scratch, I’ve resorted to saying, “Sharp, now”). We’ve been thinking about how to run our clinics this year, considering the need …

Foreign Object Damage Investigation of a Bypass Vane of an Aero-engine

Present work describes a failure analysis of bypass vane of an aero-engine. Two broken pieces of a vane have been received for failure investigation. The broken pieces of vane point towards the occurrence of four events that are impact, rubbing, denting and burning during operation. The vane is made up of an aluminium alloy AK4-1 which is an equivalent to ASTM 2618. The presence of multiple fracture features reflects that the vane surface has been impacted randomly with other parts inside engine. The deep sharp scratches and blackish deposits / soots are observed on the surface and edge of the vane. The vane has impacted by foreign object. The FOD particles consist of mainly silica and aluminium oxide along with other elements like C, Cl, S, Na, K, Ca and Cd. Microstructure of vane reveals the presence of precipitates and matrix phases

Fracture mechanics of sharp scratch strength of polycrystalline alumina

AbstractThe strength of a polycrystalline alumina containing controlled scratches introduced by translated sharp contacts is investigated and described by a multiscale fracture mechanics model. Inert strength measurements of samples containing quasi‐static and translated Vickers indentation contacts showed that scratches degraded the strength at normal contact loads an order of magnitude less than those for quasi‐static indentation. The fracture mechanics model developed to describe strength degradation by scratches over the full range of contact loads included toughening effects by crack‐wake bridging at the microscale and lateral crack‐based residual stress relaxation effects at the mesoscale. A critical element of the model is the nonlinear scaling of the residual stress field of a scratch with the normal contact load acting during scratch formation. The similarities and differences in the scratch model in comparison with prior indentation‐strength fracture mechanics models are highlighted by parallel development of both. Central to the scratch model is the use of easily controlled normal contact load as the scratch‐strength measurement variable. Scratch length and orientation are shown to have significant effects on strength. The distributions of scratch widths controlling the intrinsic strengths of as‐received samples are determined and agreement with the observed scratch dimensions is demonstrated.

Development of fatigue cracks from mechanically machined scratches on 2024‐T351 aluminium alloy—part I: experimentation and fractographic analysis

AbstractClad and unclad 2024‐T351 aluminium alloy sheets, weakened by mechanically machined scratches, were fatigued to investigate the effect of small surface damage, like scribe marks, on aircraft fuselage joints. The role of scratch cross section geometry on fatigue life of scribed components was analysed. Scratches between 25 and 185 µm deep, with 5, 25 and 50 µm root radii, were cut on sample surface by using diamond‐tipped tools. After testing, fracture surfaces were examined using a scanning electron microscope, and crack growth rates were measured by striation counting. Scratches reduced aluminium fatigue life under tensile and bending load up to 97.8% due to multiple crack nucleation at their roots. Short cracks nucleated from sharp scratches coalesced to form unique elongated cracks growing through sample thickness. Cracks initiated from scratches were typical short cracks, growing faster than conventional long cracks. Despite the different scribing process, fatigue data of regular diamond tool cut scribes can be used to conservatively predict life reduction owing to ploughed in‐service scribe marks on fuselage joints. Finite element analyses on scribed samples and the fatigue life prediction models are described in Part II of this paper.

Simple Psychological Interventions for Reducing Pain From Common Needle Procedures in Adults: Systematic Review of Randomized and Quasi-Randomized Controlled Trials.

This systematic review evaluated the effectiveness of simple psychological interventions for managing pain and fear in adults undergoing vaccination or related common needle procedures (ie, venipuncture/venous cannulation). Databases were searched to identify relevant randomized and quasi-randomized controlled trials. Self-reported pain and fear were prioritized as critically important outcomes. Data were combined using standardized mean difference (SMD) or relative risk (RR) with 95% confidence intervals (CI). No studies involving vaccination met inclusion criteria; evidence was drawn from 8 studies of other common needle procedures (eg, venous cannulation, venipuncture) in adults. Two trials evaluating the impact of neutral signaling of the impending procedure (eg, "ready?") as compared with signaling of impending pain (eg, "sharp scratch") demonstrated lower pain when signaled about the procedure (n=199): SMD=-0.97 (95% CI, -1.26, -0.68), after removal of 1 trial where self-reported pain was significantly lower than the other 2 included trials. Two trials evaluated music distraction (n=156) and demonstrated no difference in pain: SMD=0.10 (95% CI, -0.48, 0.27), or fear: SMD=-0.25 (95% CI, -0.61, 0.10). Two trials evaluated visual distraction and demonstrated no difference in pain (n=177): SMD=-0.57 (95% CI, -1.82, 0.68), or fear (n=81): SMD=-0.05 (95% CI, -0.50, 0.40). Two trials evaluating breathing interventions found less pain in intervention groups (n=138): SMD=-0.82 (95% CI, -1.21, -0.43). The quality of evidence across all trials was very low. There are no published studies of simple psychological interventions for vaccination pain in adults. There is some evidence of a benefit from other needle procedures for breathing strategies and neutral signaling of the start of the procedure. There is no evidence for use of music or visual distraction.

Out of sight, but not out of mind? Greater reported pain in patients who spontaneously look away during venepuncture.

Various external factors can influence patients' experiences of noxious stimuli, but little is known of how patients' natural behaviour may be relevant. We ascertained how often patients spontaneously look or look away during venepuncture and associated reports of pain during a previously reported experimental randomized study. The study was conducted in the outpatient department of a U.K. district general hospital. Patients were randomized to hearing 'sharp scratch' or the verbal cue 'ready?' immediately before venepuncture. Whether patients looked or looked away during needle insertion was recorded. Patients were asked to rate their pain using a verbal numerical rating score (VNRS) and verbal response scale (VRS). One hundred ninety-two patients were included; mean age 51.7 years, 55% male. During needle insertion, 73% spontaneously looked away, whereas 27% looked. There was no significant difference in the proportion of these patients assigned to the 'sharp scratch' or 'ready?' groups, nor was there any difference in mean age or gender. For the group that looked, mean VNRS was 0.48 and VRS was 1.27, significantly less than the group that looked away (mean VNRS 0.94, p = 0.014; VRS 1.61, p = 0.002). As previously reported, pain ratings between 'sharp scratch' and 'ready?' groups were not significantly different. Almost three quarters of patients spontaneously look away during venepuncture, but their pain ratings are almost twice that of the quarter of patients who look. It is unclear why this may be, but previous experimental studies indicate that observing the body when a noxious stimulus is applied can have an analgesic effect.

How Sharp is a “Sharp Scratch”? A Mixed Methods Study of Verbal Warnings Issued Before Venipuncture

Health care providers frequently issue a verbal warning before venipuncture. Communications that induce negative expectations in patients can lead to the "nocebo" response, defined as experiencing greater pain. But is this also true for "sharp scratch"? The study was conducted across 4 U.K. hospitals. Two separate surveys of health care providers and patients explored the prevalence, phraseology, rationale, and reaction to verbal warnings before venipuncture. Blinded adult patients already attending an outpatient department during a 2-week period were randomized to hearing a "sharp scratch" or the verbal cue "ready?" immediately before venipuncture. They were also asked to rate their pain (the primary outcome). 77% of 117 health care providers surveyed issued a verbal warning before venipuncture; 73% used "sharp scratch". Of 62 patients surveyed, 56% agreed that "sharp scratch" accurately describes venipuncture, and 64% agreed that they prefer "sharp scratch" to no warning. With increasing age, a preference came for an alternative warning to "sharp scratch" (P = 0.039) and to be distracted by conversation (P = 0.002). Of 192 patients in the randomized study, there was no difference in pain between the "sharp scratch" and "ready" groups. The numeric rating scores were 0.74 SD 1.06 vs. 0.88 SD 1.18, respectively. (P = 0.493). Most health care providers use the verbal warning "sharp scratch" before venipuncture. Most patients find this acceptable and prefer it to no warning. An exception may be elderly patients, who may prefer to be distracted by conversation. "Sharp scratch" makes no difference to the pain experienced compared with a verbal cue.

Interactions between Ediacaran animals and microbial mats: Insights from Lamonte trevallis, a new trace fossil from the Dengying Formation of South China

A new ichnogenus and ichnospecies, Lamonte trevallis, is formally described from the Shibantan Member limestone of the upper Ediacaran Dengying Formation, Yangtze Gorges area, South China. It is characterized by horizontal tunnels connected with short vertical burrows and surface trails. The horizontal burrows are elliptical or bilobed in transverse cross-section, preserved in full relief, and filled with carbonate intraclasts, micrites, as well as calcite and silica cements. They occur exclusively in silty, crinkled, and microlaminated layers that are interpreted as amalgamated cyanobacterial microbial mats; no burrows have been found in intraclastic layers adjacent to the microlaminated layers. The vertical traces are filled with the same material as the burrows, but they typically project through the crinkled microlaminae and are exposed on the bedding surface. The surface tracks are always preserved in negative epirelief or positive hyporelief and consist of two parallel series of either sharp scratch marks or small knobs. The burrow infill has δ18Ocarb and δ13Ccarb values distinct from, but intermediate between, microlaminated and intraclastic layers, consistent with petrographic observation that burrow infill consists of a mixture of early carbonate cements, intraclasts, and micrites. Bedding plane bioturbation intensity (20–40%)—measured as percentage of bedding plane area covered by L. trevallis traces—is comparable to similar measurements in pre-trilobite Cambrian carbonates. The exclusive occurrence of L. trevallis within microbial mats may have both taphonomic and ecological significance. These mats may have provided firm substrates and localized geochemical conditions that contributed to the structural integrity of the burrows, and they may have also facilitated early diagenetic cementation of burrow infill, thus facilitating burrow preservation. The close association of these burrows with microbial mats implies that the trace producers actively mined cyanobacterial mats to exploit oxygen or nutrient resources. The trace makers of L. trevallis were better able to utilize the resources around them than many other Ediacaran trace makers and provide an ichnological record of a flourishing benthic ecology in late Ediacaran oceans at the dawn of the agronomic revolution.

Effect of communication on pain during intravenous cannulation: a randomized controlled trial

Clinicians frequently warn patients of discomfort before potentially painful procedures, despite the lack of evidence that such communications are helpful. We aimed to compare two communications (one with, and the other without, a warning of a 'sting') immediately before i.v. cannulation in order to measure differences in perceived pain by patients during the procedure. Randomly assigned patients awaiting elective surgery received a communication immediately before i.v. cannulation consisting of either 'I am going to apply the tourniquet and insert the needle in a few moments. It's a sharp scratch and it may sting a little' (Group S) or 'I am going to apply the tourniquet on the arm. As I do this many people find the arm becomes heavy, numb and tingly. This allows the drip to be placed more comfortably' (Group NS). Cannulation pain was measured by a 0-10 verbal numerical rating score (VNRS) and five-point Likert scale. Of 101 participants, 49 were allocated to Group S and 52 to Group NS. Median VNRS pain scores with inter-quartile ranges (IQR) were 1 and 2, respectively, for both groups. Median Likert scores were 3 in Group S and 2 in Group NS with an IQR of 1 for both groups (P = 0.13). Six participants vocalized pain in Group S and none in Group NS (P = 0.01). Three participants withdrew their arm spontaneously in Group S and none in Group NS (P = 0.11). Warning patients of a 'sting' before i.v. cannulation may not be helpful.

‘Just a sharp scratch’: permanent radial, median and ulnar neuropathy following diagnostic venepuncture

An 82-year-old woman was admitted to hospital with acute left ventricular failure following a recent myocardial infarction for which she had been commenced on clopidogrel. An uneventful venepuncture in her left antecubital fossa yielded a normal full blood count and coagulation profile. Diuretics were commenced to which she responded well. Five days later she described pain, swelling and bruising of her left forearm with numbness over her thumb, index and middle fingers. Prophylactic low molecular weight heparin was discontinued and the arm elevated. Nine days later she was unable to move her left hand. Bruising extended from the shoulder to the hand with swelling distal to the antecubital fossa (Figures 1 and 2). Woody subcutaneous oedema was present around the antecubital fossa with forearm tenderness. The radial pulse was present with good capillary circulation in all fingers. Neurological examination revealed complete wrist drop, minimal finger flexion and no small muscle function of the hand. The dorsal aspect of the forearm and hand were hypersensitive, with numbness over the volar aspect of the thumb, index and middle fingers. These findings were consistent with an ischaemic neuropathy of the median, radial and ulnar nerves as a result of compartment syndrome, secondary to a compressive haematoma at the antecubital fossa following venepuncture. Surgery to relieve compartment pressures at this stage was thought to provide little chance of recovery, with the additional risk of supervening infection. Initial treatment was therefore conservative consisting of physiotherapy, vitamin B and gabapentine. An ultrasound scan confirmed the presence of a haematoma occupying the entire flexor compartment of the forearm. Nerve conduction studies revealed completely absent sensory potentials, with motor potentials 1%, 30% and 60% of normal in the radial, median and ulnar nerves respectively. This confirmed a severe subtotal axonotmesis of the radial nerve with partial axonal injury to the median and ulnar nerves. The prognosis was one of permanent major neurological deficit and despite intensive hand physiotherapy there was little functional recovery 1 year later.

Mechanical properties of porous, electrosprayed calcium phosphate coatings

Mechanical properties of calcium phosphate coatings (CaP), deposited using the electrostatic spray deposition (ESD) technique, have been characterized using a range of analytical techniques, including tensile testing (ASTM C633), fatigue testing (ASTM E855), and scratch testing using blunt and sharp scratch styli. Moreover, a simple explantation procedure was successfully introduced using ESD-coated, threaded dental implants to characterize the mechanical performance of CaP coatings qualitatively under conditions that mimic clinical situations as close as possible. Generally, all analysis techniques revealed that ESD coatings need to be crystallized in order to ensure interfacial adhesion to the substrate and sufficient mechanical strength of the superficial reticular structure. Crystalline carbonated hydroxyapatite coatings (CHA, heat-treated at 700 degrees C) were resistant to fatigue as well as to plastic ploughing deformation by means of various scratch styli, and the fragile surface structure of ESD coatings was maintained to a large extent after unscrewing CHA-coated dental implants from femoral condyles of goat cadavers. From these experiments, it was concluded that interfacial adhesion of crystalline CHA ESD coatings to the titanium substrate was sufficient, but that mechanical strength of the superficial architecture of ESD coatings need to be optimized for applications where high shear and compressive stresses are imposed onto the rather fragile coating surface of reticular ESD morphologies.

Effects of Wafer Thinning Condition on the Roughness, Morphology and Fracture Strength of Silicon Die

A systematic investigation on the effects of wafer thinning process on the surface roughness, morphology and fracture strength of silicon chips was conducted. The results of the study suggest that the fracture strength of the silicon chips was determined predominantly by the geometry and scratch tip sharpness of a few large and deep scratches formed during wafer thinning. Although additional polishing by dry-polishing technique after traditional mechanical coarse/fine grinding could greatly improve the average roughness of the die surface, it would not further strengthen the silicon chips because the dry polishing could not successfully remove large scratches or reduce the scratch size. Plasma etching was found to have a high effectiveness in fracture strength improvement. Mechanism study shows that plasma etching turned the very sharp and large scratches into U-grooves, leading to a reduced stress concentration, hence, a much improved fracture strength.

Cleanability of Soiled Stainless Steel as Studied by Atomic Force Microscopy and Time of Flight Secondary Ion Mass Spectrometry

The hygienic status of food contact surfaces can deteriorate with wear. Effective cleaning regimes must remove any adsorbed organic material as well as microorganisms. Previous work has determined the extent of surface wear occurring on a stainless steel surface within the food industry, and we have reproduced representative samples in vitro. Two surface analytical techniques, atomic force microscopy and time of flight secondary ion mass spectrometry were combined with fluorescence microscopy to give detailed analysis of stainless steel surfaces fouled with starch and milk powder, then cleaned with water either by a spray or brushing method. It was found that the surface cleanability is affected by the cleaning regime and the surface roughness, not only the average vertical roughness but also by the shape of the surface defects, with sharp scratches more difficult to clean than wider surface defects. Spray cleaning with distilled water was found to be a selective method by preferentially removing proteinaceous material more easily than fatty acid ester material. The analytical techniques employed provided information on selective cleanability and surface topography at a hitherto unexplored level, and the information gained may be of value in the design and investigation of novel cleaning regimes and hygienic surfaces.

酸化銀電池の電解液漏洩封止に関する研究 ２ ガスケットの応力解析に基づく封止面のすきまの検討

Clearance between anode can and gasket is evaluated by finite element method. First step of the analysis is to get contact stresses between gasket and anode can as axis-symmetric elastic deformation. Young's modulus of nylon from which the gasket is made is estimated from stress strain curve and from stress relaxation test data of nylon test pieces. Loads and boundary conditions are decided from difference between the shape of gaskets in the batteries and taken out from the batteries. In result, maximum contact stress is about 200MPa on periphery of anode can. Second step of the analysis is clearance estimation between gasket and anode can of which surface is modeled by an isosceles triangle shape. Relation between contact stresses and clearances is given. In macroscopic, no clearance exists near the periphery of anode can. Scratch shape on the anode can is important. If the ratio of depth to width is over 0.1 times, clearances exist in 200MPa. In electron microscopic observation, sharp scratches exist in the surface of anode can. Therefore, as the time the battery is made, only microscopic clearances exist, and no macroscopic clearances exist, between the gasket and anode can.