Sudden unexpected death resulting from an anomalous hypoplastic left coronary artery

We present a case of sudden death in a 24-year-old, healthy white female who was physically active and participated in sports, including soccer. Two weeks prior to her death, an insurance physical examination revealed an abnormal electrocardiogram which demonstrated flipped T waves in the anterior leads. There was no other remarkable medical history. At autopsy, only one coronary ostium was demonstrated and it originated from the right aortic sinus. Approximately 0.8 cm from this right coronary artery (RCA) ostium, a left coronary artery (LCA) branched off the RCA at a 90-degree angle. The LCA had luminal diameter of 0.4 m but the LCA had a luminal diameter of only 0.1 cm. The LCA coursed anterior to the base of the pulmonary artery and down the anterior ventricular septum reflecting the usual course of the left anterior descending (LAD) coronary artery. The LCA and RCA paths appeared to merge or terminate at the anterior left ventricular myocardium which was discolored gray, a process that involved the inner and middle thirds of the myocardium. Based on the autopsy findings, we certified the cause of death as a probable arrhythmia due to myocardial fibrosis and dystrophic calcification resulting from complications of an anomalous hypoplastic left coronary artery. Anomalies of coronary arteries have been classified and studied at autopsy and by clinical angiography. Coronary artery anomalies can be divided into minor and major forms with major anomalies often resulting in cardiac dysfunction that may cause failure and death. Minor anomalies, in general, have no pathophysiological significance and are compatible with life. Minor anomalies include variations in number and location of coronary ostia. A single coronary ostia is exceedingly rare in hearts with no other congenital malformations. The prognostic significance can be unpredictable. A single coronary artery has the potential to be dangerous if obstructed at its main stem, or if it branches at an acute angle. Additionally, hypoplasia of one or more coronary arteries has been found to be associated with sudden death.     

Transthoracic Doppler echocardiography of normally originating coronary arteries in children

Transthoracic Doppler color flow and spectral velocity patterns of normal coronary arteries in children have not been well studied. We designed this study to evaluate coronary artery flow velocity characteristics in normal and hypertrophied hearts. Sixty-eight children with optimal two-dimensional echocardiographic images of the left coronary artery (LCA) and right coronary artery (RCA) were prospectively studied. The heart was normal in 45 children, and 23 had left and/or right ventricular hypertrophy assessed by echocardiography (mean age 5.8 versus 5.2 years, p = NS). Color flow signals were detected in the LCA in 63(92%) of the 68 children studied, and pulsed Doppler spectral waveforms were recorded in 47 (69%). The latter were recorded in 26 (58%) of 45 normal children and in 21 (91%) of 23 children with left ventricular hypertrophy. Diastolic RCA flow signals were detected mostly in those with right ventricular hypertrophy (10 of 10). Higher levels of LCA maximum diastolic velocity (42 +/- 23 versus 24 +/- 6 cm/sec, p = 0.0004), increased diastolic flow (16 +/- 15 versus 6 +/- 4 ml/min, p = 0.01), and delayed time to peak diastolic velocity expressed as a percentage of diastolic spectral duration (38% +/- 14% versus 20% +/- 8%, p = 0.0001) were observed in children with left ventricular hypertrophy than in those in normal children. A strong correlation was present between Doppler-derived LCA flow and left ventricular mass/m2 (r = 0.7, p = 0.001). In normal hearts, LCA spectral velocity pattern did not change with increasing age, but the time velocity integral became progressively larger, resulting in a strong correlation with weight (p < 0.001, r = 0.78). This study demonstrates (1) LCA flow signals can be detected and quantitated in the majority of children with and those without left ventricular hypertrophy. (2) Left ventricular hypertrophy is associated with increased LCA flow, higher diastolic velocity, and delayed peak diastolic velocity. (3) RCA flow signals are mostly detected when there is right ventricular hypertrophy. Studies on larger groups of patients are needed to further confirm our observations and to enhance understanding of coronary artery flow reserve.     

Hybrid Life-Cycle Inventory for Road Construction and Use

Life-cycle assessment (LCA) is a technique that is used worldwide by clients and their design team to assess the impact of their projects on the environment. The main advantage of LCA is in supporting decision making with quantitative data. LCA inventories can be either fully developed or streamlined. Fully developed LCAs are time-consuming and costly to prepare. Streamlined LCAs can be used as an effective decision-making tool when considering environmental performance during the design process, but with a loss of inventory completeness. Acknowledging the advantages and disadvantages of both types of LCA, this paper proposes a hybrid LCA method that uses input-output data to fill in those gaps routinely left in conventional LCA inventories. The developed hybrid LCA method is demonstrated using a life-cycle energy study of eight different road designs, including vehicle manufacture, maintenance, replacement, and operation. It was found that the road construction process was initially the most important, but in the long run the manufacture, use, and maintenance of vehicles using the road (which are an inevitable consequence of road construction) became paramount.     

Extrahepatic deposition and cytotoxicity of lithocholic acid: studies in two hamster models of hepatic failure and in cultured human fibroblasts

Effects of bile acids on tissues outside of the enterohepatic circulation may be of major pathophysiological significance under conditions of elevated serum bile acid concentrations, such as in hepatobiliary disease. Two hamster models of hepatic failure, namely functional hepatectomy (HepX), and 2-day bile duct ligation (BDL), as well as cultured human fibroblasts, were used to study the comparative tissue uptake, distribution, and cytotoxicity of lithocholic acid (LCA) in relation to various experimental conditions, such as binding of LCA to low-density lipoprotein (LDL) or albumin as protein carriers. Fifteen minutes after i.v. infusion of [24-(14)C]LCA, the majority of LCA in sham-operated control animals was recovered in liver, bile, and small intestine. After hepatectomy, a significant increase in LCA was found in blood, muscle, heart, brain, adrenals, and thymus. In bile duct-ligated animals, significantly more LCA was associated with blood and skin, and a greater than twofold increase in LCA was observed in the colon. In the hepatectomized model, the administration of LCA bound to LDL resulted in a significantly higher uptake in the kidneys and skin. The comparative time- and concentration-dependent uptake of [14C]LCA, [14C]chenodeoxycholic acid (CDCA), and [14C]cholic acid (CA) in cultured human fibroblasts was nonsaturable and remained a function of concentration. Initial rates of uptake were significantly increased by approximately tenfold, with decreasing hydroxylation of the respective bile acid. After 1 hour of exposure of fibroblasts to LCA, there was a significant, dose-dependent decrease in mitochondrial dehydrogenase activity from 18% to 34% of the control, at LCA concentrations ranging from 1 to 20 micromol/L. At a respective concentration of 100 and 700 micromol/L, CDCA caused a 35% and 99% inhibition of mitochondrial dehydrogenase activity. None of the bile acids tested, with the exception of 700 micromol/L CDCA, caused a significant release of cytosolic lactate dehydrogenase into the medium. In conclusion, we show that bile acids selectively accumulate in nonhepatic tissues under two conditions of impaired liver function. Furthermore, the extrahepatic tissue distribution of bile acids during cholestasis may be affected by serum lipoprotein composition. At a respective concentration of 1 and 100 micromol/L, LCA and CDCA induced mitochondrial damage in human fibroblasts, after just 1 hour of exposure. Therefore, enhanced extrahepatic uptake of hydrophobic bile acids during liver dysfunction, or disorders of lipoprotein metabolism, may have important implications for bile-acid induced cytotoxic effects in tissues of the systemic circulation.     

Review of Life-Cycle Assessment Applications in Building Construction

Life-cycle assessment (LCA) has been used to assess product development processes “from cradle to grave” for many years. With the current push toward sustainable construction, LCA has gained importance as an objective method to evaluate the environmental impact of construction practices. A substantial amount of construction-related LCA work has been published recently; however, most of this work has been fragmented and a systematic compilation of this literature has not been undertaken. This article presents a structured review of building construction-related LCA literature, classified under four categories: LCA applications for construction products selection; LCA applications for construction systems/process evaluation; LCA tools and databases related to the construction industry; and LCA methodological developments related to the construction industry. Current challenges for using LCA in construction are discussed and potential areas for future research are highlighted. This review and similar efforts may provide the construction industry and associated researchers the necessary background to make better-informed construction decisions and assist the development of an agenda for further research.     

Influence of age on enzyme activities of pyrimidine metabolism in the chicken heart

We and others found that cardioprotection is acquired not only soon after, but also 24 h after ischemic preconditioning in canine and rabbit myocardial infarction models (second window of protection). However, a second window phenomenon against myocardial infarction was dependent on species limitations and has not been observed in porcine hearts. In this study, we examined whether the "second window of protection" against myocardial infarction is observed in the rat heart. In the ischemic preconditioning (IP) group, the left main coronary artery (LCA) of rats was occluded four times for 3 min. each separated by reperfusion for 10 min. After 0, 3, and 24 h, the rats were subjected to a 20-min LCA occlusion followed by 48-h reperfusion. At 0 and 24 h after IP, infarct size and the incidence of ventricular fibrillation (VF) during ischemia were significantly reduced compared with corresponding sham-operated groups without preconditioning. After 3 h of IP, there were no differences either in the incidence of VF during ischemia or in infarct size. Manganese superoxide dismutase (Mn-SOD) content in ischemic (LCA) region of myocardium significantly increased as compared with that of sham-operated rats 24 h after IP. Treatment with N-2-mercaptopropionyl glycine, an antioxidant and a hydroxyl radical scavenger, during IP abolished the early-phase (0 h after IP) and late-phase (24 h after IP) cardioprotection and the corresponding late increase in Mn-SOD content. These results indicate that a "second window of protection" against myocardial infarction also exists in rat hearts and the induction of an intrinsic scavenger, Mn-SOD, via free radical production during IP may be important in the second window of protection.     

Oligomerization properties of ERp29, an endoplasmic reticulum stress protein

Leber's congenital amaurosis (LCA) is the earliest and most severe of all inherited retinal dystrophies. Recently, we mapped an LCA gene to chromosome 17p13.1 (LCA1) and ascribed the disease to mutations of the retinal guanylate cyclase (ret GC) gene in a subset of families of North African ancestry. Owing to the genetic heterogeneity of LCA and considering that LCA1 results from an impaired production of cGMP in the retina (with permanent closure of cGMP-gated cation channels), we hypothesized that the activation of the cGMP phosphodiesterase (PDE) could trigger the disease by lowering the intracellular cGMP level in the retina. The rod and cone cGMP-PDE inhibitory subunits were regarded therefore as candidate genes in LCA. Here, we report the exclusion of five rod and cone cGMP-PDE subunits in LCA families unlinked to chromosome 17p13.     

Testing Main Effects and Interactions in Latent Curve Analysis.

A key strength of latent curve analysis (LCA) is the ability to model individual variability in rates of change as a function of 1 or more explanatory variables. The measurement of time plays a critical role because the explanatory variables multiplicatively interact with time in the prediction of the repeated measures. However, this interaction is not typically capitalized on in LCA because the measure of time is rather subtly incorporated via the factor loading matrix. The authors' goal is to demonstrate both analytically and empirically that classic techniques for probing interactions in multiple regression can be generalized to LCA. A worked example is presented, and the use of these techniques is recommended whenever estimating conditional LCAs in practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introducing a multi-criteria indicator to better evaluate impacts of rare earth materials production and consumption in life cycle assessment

Life cycle assessment （LCA） is based on the basic principles of sustainable development. LCA method demonstrated its efficiency in providing a systematic environmental assessment approach of a product or a process. The effectiveness and efficiency of these methods lies in the fact that they take into account all life cycle stages of a product, from the extraction of raw materials to end of life treatment （recycling, ...） through an assessment covering different impact categories such as climate change, human health, ecosystems and resources. Existing LCA indicators reflect different issues surrounding resource depletion, creating inconsistency and moreover confusion among LCA practitioners. The evaluation of different life cycle impacts assessment （LCIA） methods done by EC JRC showed that available models did not address the same parameters： short- vs long-term, stock vs backup technology, etc. It also showed that if the correlation between the methods was sufficient for some resources, others such as rare earth elements showed a high level of inconsistency between methods. It was therefore necessary to develop a relevant indicator and harmonized assessment of impacts on resources in LCA. Furthermore, a resource strategy indicator based on the three pillars of sustainable development （eco- nomic, environmental and social） would better address wider challenges and making it a more powerful decision making tool. This study aimed to introduce an indicator for evaluating the strategy implications of metal resources for products and to compare different ways of production resulting from extraction of raw materials or recycling, with a special focus on rare earth materials. The indicator would assess the impacts based on a reserve-resource vision [BGS NERC] and the evolution over time and founded over three pa- rameters： technical feasibility, economic viability and political stability （including social and environmental aspects） in representing countries.     

中国钢铁产品全生命周期评价理论与实践

阐述了全生命周期评价的基本原理和内涵,分析了全生命周期评价在国内外钢铁行业的应用现状、差距及研究进展情况,论述了钢铁企业开展全生命周期评价的重要意义,研究了中国政府、行业协会、钢铁企业、咨询机构等在推进绿色设计产品评价技术规范系列标准等方面开展的相关工作。提出钢铁行业全生命周期评价推广与应用的具体建议,探讨了发展方向,对钢铁企业开展生命周期评价具有一定的指导意义。     

Accommodation without feedback suggests directional signals specify ocular focus

Accommodation was monitored continuously under open-loop conditions while subjects viewed a sinusoidally oscillating sine-wave grating (0.2 Hz; +/- 1 D; 2.7 c/d; 0.56 contrast) in a Badal optometer. The target was illuminated by monochromatic light (590 nm) or white light (3000 K) with longitudinal chromatic aberration (LCA) normal, doubled, neutralized and reversed. Subjects (12) accommodated well in white light with LCA normal and doubled (mean gains = 0.85 and 0.94), gain was reduced in the neutralized condition (0.54), in monochromatic light (0.43), and especially when LCA was reversed (0.30). The results suggest that accommodation responds to changes in the relative contrast of spectral components of the retinal image and perhaps to the vergence of light.     

Small amounts of chromatic aberration influence dynamic accommodation

The prevailing view of accommodation is that the eye changes focus to maximize luminance contrast by trial and error. Negative feedback is considered essential in this view because luminance contrast provides no directional information. Fincham proposed an alternate view in which longitudinal (axial) chromatic aberration (LCA) provides a directional stimulus for accommodation. For spatial frequencies above approximately 0.5 cpd contrast of the retinal image is different for long, middle, and short spectral waveband components of the image. We varied the amount of LCA in small steps (0.25 D) to determine how much LCA is needed to enhance or impair the response. An infrared optometer monitored accommodation continuously while subjects viewed a yellow/black square-wave grating (3.5 cpd) in a Badal stimulus system. The yellow/black grating was produced by superimposing red (600 nm) and green (520 nm) gratings, and LCA was increased, decreased, neutralized, and reversed by repositioning the red grating component along the axis of the optical system. Target vergence was modulated sinusoidally (0.2 Hz) over a 1 D range (1.5 to 2.5 D) and gain and phase-lag of the accommodation response were determined by Fourier analysis. Subjects accommodated well as long as a normal amount of LCA was present--0.5 D in the correct direction enhanced accommodative gain, and 0.25 D in the reverse direction markedly inhibited the response. We conclude that the contrast of the retinal image in different spectral wavebands specifies focus of the eye, and provides a powerful directional stimulus for reflex accommodation.     

LCA在钢铁生产中的应用研究

近年来,LCA已发展成为一种国际公认的生态与环境管理工具。介绍了LCA的理论及其在钢铁工业中的应用状况,并用LCA方法分析了钢铁生产工艺的温室气体排放状况,提出了建立可持续钢铁生产工艺应采取的措施。     

LCA评价方法及其在有色金属行业中的应用

分析当前国内外社会经济发展中所面临的环境问题和我国今后国民经济发展所要承担减排任务的艰巨性,从循环经济、清洁生产等方面出发,应用具有全程控制理念的生命周期（LCA）评价理论的基本原理和实施框架,分析传统＂末端治理＂的应用瓶颈、实施LCA评价的可能性和必要性,并依据国内外LCA评价方法的研究及在有色金属行业中的应用现状,分析LCA评价理论在有色金属工业应用中存在的问题,提出了进一步完善LCA评价方法的建议措施.     

Transesophageal echocardiography to assess embolic risk in patients with atrial fibrillation. ELAT Study Group. Embolism in Left Atrial Thrombi

BACKGROUND: Transesophageal echocardiography visualizes the left atrium and its appendage, thrombi, and spontaneous echocardiographic contrast. OBJECTIVE: To assess the association of transesophageal echocardiographic characteristics with stroke or embolism in atrial fibrillation. DESIGN: Multicenter observational follow-up study. SETTING: Hospitals in Austria and Slovakia. PATIENTS: 409 outpatients with nonrheumatic atrial fibrillation and without recent stroke. INTERVENTION: Patients with thrombi received anticoagulation, and patients without thrombi received aspirin. MEASUREMENTS: Primary events were stroke or embolism. Secondary events were death not caused by stroke or embolism and need for anticoagulation. RESULTS: In the left atrium or left atrial appendage, 10 patients (2.5%) had thrombi and 47 (12%) had spontaneous echocardiographic contrast. The appendage had a mean (+/- SD) length of 44+/-10 mm, a mean width of 23+/-6 mm, and a mean area of 5.8+/-2.5 cm2. Follow-up ranged from 1 to 74 months (mean, 58 months). Fifty patients had stroke or embolism, 53 died of a cause other than stroke or embolism, and 38 required anticoagulation. On univariate analysis, thrombi (risk ratio, 3.9 [95% CI, 1.4 to 10.1]; P = 0.009), length of the left atrial appendage (risk ratio, 1.6 [CI, 1.05 to 2.5]; P = 0.03), and width of the left atrial appendage (risk ratio, 2.4 [CI, 1.2 to 4.81; P = 0.01) were associated with stroke or embolism. Multivariate analysis identified hypertension (risk ratio, 3.6 [CI, 1.8 to 8.4]; P = 0.001), previous stroke (risk ratio, 3.7 [CI, 1.5 to 7.5]; P = 0.002), and age (risk ratio, 1.1 [CI, 1.0 to 1.11; P < 0.001) as risk factors for stroke or embolism and provided evidence of an association between thrombi and stroke or embolism (risk ratio, 2.4 [CI, 0.9 to 6.9]; P = 0.09). CONCLUSIONS: In outpatients with atrial fibrillation and without recent stroke, thrombi of the left atrium or left atrial appendage and length and width of the left atrial appendage were associated with stroke or embolism in univariate analysis. In a multivariate analysis, age, hypertension, and previous stroke were risk factors for stroke or embolism, and thrombi of the left atrium or left atrial appendage were possible risk factors. In these patients, history may be more useful than transesophageal echocardiography for the assessment of embolic risk.     

Anomalous origin of the left coronary artery from the pulmonary artery in an adult: tubular reconstruction of the left main coronary artery under coronary perfusion

A 38-year-old female with anomalous origin of the left coronary artery (LCA) from pulmonary artery was surgically corrected by tubular reconstruction of the left main coronary artery (LMCA) using the pulmonary artery wall, and this repair was performed under beating heart. Thus, the pulmonary artery was divided above the orifice level and just above the pulmonary valve, and the commissure between nonfacing and left side sinuses was dissected away from the pulmonary artery wall to obtain lateral flaps. The pulmonary artery defect was reconstructed with a roll using an autologous pericardial patch, while the detached commissure was suspended on the pericardial patch. The long tube constructed using pulmonary artery tissue was anastomosed to the anterior aspect of the ascending aorta. These procedures were performed under beating heart simply by clamping the LMCA, since the preoperative myocardial contrast echocardiography confirmed the adequate coronary collateral flow from the right circulation. The postoperative course was uneventful, and a coronary artery angiogram demonstrated a widely patent LMCA. Our experience suggests that, in adult cases, this procedure could be performed without myocardial ischemia simply by clamping the LMCA because of well-developed coronary collateral arteries. The safety of this technique could be confirmed by myocardial contrast echocardiography.     

Gestational choriocarcinoma metastatic to the brain treated successfully by stereotactic radiosurgery and chemotherapy

This report analyzes the intracorporal lengths of 236 consecutive organically impotent men who underwent insertion of a penile prosthesis. The average right or left intracorporal length in this series was 20.9 cm, with a standard deviation of 2.2 cm. Intracorporal length ranged from 14-27 cm. This data may be used as reference ranges for penile prosthesis manufacturers, and for Urologists who implant prostheses or perform penile lengthening procedures.     

Clinical utility of two-dimensional magnetic resonance angiography in detecting coronary artery disease

AIMS: The accuracy of magnetic resonance angiography in detecting proximal coronary artery stenoses is unclear. We postulated that fast magnetic resonance angiography is capable of (1) imaging proximal coronary arteries, and (2) detecting stenoses of > or = 50% of their luminal diameter. METHODS AND RESULTS: Thirty-five patients, referred for analysis of angina pectoris, underwent both conventional angiography and magnetic resonance angiography of coronary arteries. A fast k-space segmented gradient-echo technique was used during breath-holds. Two observers, blinded to the results of conventional angiography, independently analysed the magnetic resonance studies for (1) length of visualized segments, and (2) presence of signal voids indicative of stenoses. From 140 proximal arteries, 15 (11%) were excluded because of incomplete imaging or degraded image quality. Mean length of the visualized segments was 9 +/- 4 mm for the left main, 62 +/- 16 mm for the left anterior descending, 21 +/- 9 mm for the left circumflex and 89 +/- 32 mm for the right coronary artery. Sensitivity for detecting > or = 50% luminal diameter stenoses was 0.00 for the left circumflex, 0.53 for the left anterior descending coronary artery, 0.71 for the RCA and 1.00 for the left main artery. Specificity varied from 0.73 for the left anterior descending coronary artery to 0.96 for the left circumflex. Inter-observer agreement was 0.90. CONCLUSION: Thus, segmented magnetic resonance angiography is capable of non-invasive imaging of proximal coronary anatomy. Its good accuracy in detecting left main coronary artery disease, intermediate accuracy in detecting right coronary artery and left anterior descending coronary artery stenoses, and low accuracy in detecting left circumflex lesions fit within a range of sensitivities and specificities found by others. Further technical advances are necessary to make the technique clinically robust.     

Electrophysiological effects of acute dilatation in the isolated rabbit heart: cycle length-dependent effects on ventricular refractoriness and conduction velocity

BACKGROUND: Acute ventricular dilatation has important electrophysiological effects: Dilatation shortens action potential duration and refractoriness without an apparent effect on conduction velocity. These effects have been implicated as a potential mechanism of arrhythmias in patients with congestive failure. Because the influence of cycle length on these phenomena has not been studied, we examined the effects of dilatation during ventricular pacing at cycle lengths from 1000 to 150 ms. METHODS AND RESULTS: Thin epicardial layers were created in isolated, perfused rabbit left ventricles (n=7). A fluid filled latex balloon was secured in the left ventricle to dilate the left ventricle. Mapping was performed with 248 epicardial electrodes. Longitudinal conduction velocity (76+/-1 cm/s; mean+/-SEM) and transverse conduction velocity (26+/-1 cm/s) were not influenced by dilatation at any cycle length. In contrast, the effects of dilatation in decreasing left ventricular effective refractory period (ERP) were significantly greater at shorter drive cycle lengths: The decrease in ERP was 2+/-2 ms (a 1% change) at a drive cycle length of 1000 ms and 18+/-4 ms (a 20% change) at a drive cycle length of 150 ms. In 10 additional intact, isolated perfused rabbit hearts, dilatation decreased ERP to a greater degree during 250 ms drive cycle length pacing than during pacing at 400 ms (25+/-4 versus 16+/-3 ms; P=.01). CONCLUSIONS: Acute dilatation exaggerates the normal rate-dependent shortening of refractoriness but does not influence transverse or longitudinal conduction velocity. This observation suggests that the electrophysiological effects of acute dilatation may be greater during tachycardia than at slower cycle lengths. This may have implications for arrhythmias in patients with congestive heart failure.     

Evaluation on the contribution of steel products to environmental improvement from LCA perspectives

High functionality given to steel products results in an increase of environmental loads in the steelmaking stage. However,at the stage of their utilization,the high-functional steel products prove to be more environmentally friendly than their conventional counterparts in many cases. In view of this contradiction,the evaluation on the contribution of steel products to environmental improvement requires a more integrated approach-Life Cycle Assessment ( LCA ) ,which incorporates the effects over the products'entire life cycles. This paper discusses the relationship between the improvement of steel products'performance and the according environmental impact from the entire life cycle perspectives. How to evaluate and assess the contribution of high-functional steel products to environmental improvement using LCA method is explained in detail. Two case studies of Baosteel are given to substantiate the effectiveness of LCA as a scientific and systematic method for eco-material evaluation or eco-design: ① For a power transformer,by replacing silicon steel B30G130 with B30P110,the carbon dioxide emissions were reduced by 15. 1% over the life cycle of the transformer. ② Tinplate steel of Baosteel used for two-piece steel cans experienced six reductions in thickness from 0. 28 mm to 0. 225 mm,which results in a 14. 5% emission reduction over the life cycle of two-piece steel cans.