A reliable frozen section technique for basal cell carcinomas of the head and neck

Basal cell carcinomas (BCCs) of the head and neck treated by conventional techniques of surgical excision, curettage, cryotherapy and radiation therapy have recurrence rates of up to 42%. Mohs micrographic surgery (MMS) decreases the recurrence rate but can be expensive, delay definitive reconstruction and is limited in its availability.The authors report a series of 50 patients with head and neck BCCs treated by a surgeon-directed ‘en face’ frozen section technique that immediately evaluates the entire peripheral and deep margins during BCC resection, and potentially offers a more efficient and equally effective alternative to MMS.Patient demographics, pathology results, operative time, technique and outcomes are all reported. With a mean follow-up of three years, there was only one recurrence (1.7%). Mean total operative time was 1 h 47 min. The authors conclude that this surgeon-directed ‘en face’ frozen section technique does not require any specialized training, enables more rapid and reliable results than standard frozen section techniques that are currently used, and provides outcomes equivalent to MMS in the surgical treatment of head and neck BCCs.     

Novel Approach for Suppressing Cutting Dust Using Foam on a Fully Mechanized Face with Hard Parting

The cutting dust created by the shearer drum is the main source of dust on a fully mechanized coal face. However, overexposure to respirable dust may cause pneumoconiosis in coal workers, while coal dust may lead to serious explosions. The fully mechanized face known as II1051 Face, found at the Zhuxianzhuang Coal Mine located in east China, generates dust by way of the drum on a high-power shear. The coal seam involves hard rock parting so there is a high concentration of cutting dust when the shearer is working. Thus, we developed a new foam dust suppression method with an air self-suction system based on an analysis of the dust generation characteristics that suppressed the shearer cutting dust level. The new foam system was evaluated in a field test where the dust concentration was measured at two points. The results showed that the foam reduced the cutting dust concentration significantly. The respirable dust exposure levels were reduced from 378.4 mg/m³to 53.5 mg/m³and the visibility was enhanced dramatically. Thus, we conclude that our new foam system is highly efficient at capturing cutting dust, and it has a much lower water consumption.

[Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: Contact angle of cutting dust sample, migration trajectory of cutting dust, technological process for suppressing shearer cutting dust using foam, the layout of the foam dust suppression system on coal face, real object of the air self-suction type foam generator, the special foam nozzle used for shearers, relevant experimental results of the air self-suction foam system.]     

整脊结合局部推拿治疗青少年假性近视临床观察

目的：探讨整脊推拿结合局部面部推拿手法治疗青少年假性近视的疗效,寻求一种安全有效的中医传统治疗方法。方法选择符合纳入标准的7～18岁假性近视中小学生80例,随机分为治疗组和对照组。治疗组给予整脊推拿结合局部面部推拿手法治疗;对照组给予局部面部推拿手法治疗。检测视力和脑血流图检测值变化幅度,评价治疗效果。结果两组青少年假性近视患者,经治疗后的视力、脑血流图检测值变化及疗效评价比较均有统计学意义,且治疗组优于对照组（P＜0.05）。结论整脊推拿结合局部面部推拿手法能够改善假性近视青少年的视力水平,是一种安全有效的中医传统治疗方法。     

不同胆囊收缩素-8水平男大学生新面孔识别感觉寻求任务诱导的事件相关电位差异

目的 观察新面孔识别感觉寻求任务诱导下高低胆囊收缩素-8（CCK-8）组之间的脑区事件相关电位（ERP）差异,寻找治疗成瘾的新方法.方法 从大连市海事大学随机被抽取的男新生100人,按照CCK-8值高低排序,4分位法,取高、低CCK-8组[（176.80± 118.05） mmol/L,（43.13± 13.35） mmol/L;t=3.90; P=0.00]各25名,年龄范围19～21岁,均为右利手,视力正常.行为观察包括新面孔识别任务下反应时和正确率,使用感觉寻求量表观察感觉寻求;高低CCK-8组在新面孔识别任务诱导下ERP被记录.行为测试采用t检验,脑区激活观察采用三个混杂因素交互作用的反复测量方差分析,包括脑区（左、中、右）＆#215;脑叶（额区、中央区、顶区）＆#215;组别（高、低CCK-8）.结果 新面孔识别任务下,行为学结果差异无统计学意义（P＞0.05）,P300脑区的主效应显著[F（1.60,35.21）=6.61,P=0.01];P300脑叶主效应显著[F（1.51,33.17）=3.41,P=0.26];P300脑叶和脑区之间的交互效应显著[F（2.01,44.12）=13.27,P=0.00];P300脑叶、脑区、组别三者之间的交互效应趋于显著[F（201,44.12）=2.97,P=0.06].结论 CCK8影响感觉寻求,高CCK水平,高感觉寻求能力.     

Economic scarcity alters the perception of race

When the economy declines, racial minorities are hit the hardest. Although existing explanations for this effect focus on institutional causes, recent psychological findings suggest that scarcity may also alter perceptions of race in ways that exacerbate discrimination. We tested the hypothesis that economic resource scarcity causes decision makers to perceive African Americans as “Blacker” and that this visual distortion elicits disparities in the allocation of resources. Studies 1 and 2 demonstrated that scarcity altered perceptions of race, lowering subjects’ psychophysical threshold for seeing a mixed-race face as “Black” as opposed to “White.” In studies 3 and 4, scarcity led subjects to visualize African American faces as darker and more “stereotypically Black,” compared with a control condition. When presented to naïve subjects, face representations produced under scarcity elicited smaller allocations than control-condition representations. Together, these findings introduce a novel perceptual account for the proliferation of racial disparities under economic scarcity.When the economy declines, racial minorities are hit the hardest. Although socioeconomic and health disparities typically exist between White and racial minority Americans (1, 2), these disparities tend to expand dramatically during economic crises. For example, during the economic recession of 2007–2009, median household wealth decreased by 16% for White Americans, whereas it decreased by 53% for African Americans (3). These widening disparities are often described in policy circles as an amplification of existing structural and institutional inequalities (4). For example, because of societal disparities in education and income, racial minorities are more likely than majority White Americans to be employed in blue-collar industries—the very industries most vulnerable to economic duress (5, 6). By this account, increased disparities during recession reflect longstanding and unyielding societal structures.However, experimental social psychology research suggests that these scarcity effects are not solely a consequence of institutional and societal structures. Indeed, scarce conditions may also influence how one perceives and acts toward others, in ways that change according to one’s particular social goals. In research on arbitrarily defined social groups (in which structural factors were held constant) scarcity and resource competition fostered distrust and antipathy and promoted discriminatory resource allocations between groups (7–9). Other research has shown that scarcity leads perceivers to devalue another person’s worth and deservingness to justify withholding resources from them (10, 11). These findings suggest that economic scarcity changes the way individuals respond to members of other social groups in a manner that facilitates discrimination, beyond the effect of societal structures.How might scarcity effects on social perception contribute to widening racial disparities during economic recession? Prior research has shown that scarcity increases decisions to exclude biracial individuals from the White majority group (12, 13), perhaps to preserve resources. However, mounting evidence suggests that even perceptions of race are malleable and that biases in race perception have implications for the expression of prejudice. That is, although race is often regarded as fixed and veridically perceived (14), representations of a person’s race or ethnicity can shift as a function of the perceiver’s social goals and motivations (15–19). For example, in prior work we found that greater antiegalitarian motives related to the visual perception of African American faces as “Blacker” (20). Such perceptual shifts are consequential: discrimination against African Americans is magnified for those viewed as more prototypically “Black” (i.e., as having darker skin tone and more Afrocentric features) (21), such that they are more likely to be socially excluded, shot when unarmed in a police training task, and sentenced to death after a guilty verdict (22–24). Given these effects, we proposed that economic scarcity may lead perceivers to distort their visual representations of African Americans, seeing them as “Blacker,” which in turn facilitates economic discrimination against them. This hypothesis, which proposes that scarcity shifts the perceptual processing of race (beyond mere shifts in category membership), represents an especially pernicious process through which economic factors promote discrimination. In the studies described herein, we used a psychophysics approach to examine perceptual thresholds and representations of race to rigorously probe the effect of perceived economic scarcity on the visual processing of race.In an initial test, we examined the relationship between beliefs about economic competition and visual representations of race. Seventy American subjects, none of whom were Black, were recruited for a study on “their ability to determine a person’s racial identity” (Methods). First, subjects completed a questionnaire containing items assessing their concerns about zero-sum economic competition between Black and White Americans (e.g., “When Blacks make economic gains, Whites lose out economically”) embedded among other items irrelevant to issues of race. Next, subjects completed a race identification task in which they viewed, in fully randomized order, a series of 110 morphed faces ranging in appearance from 100% Black to 100% White at 10% increments (Fig. 1A), classifying each face as “White” or “Black” (Fig. 1B). Our interest was in whether belief in zero-sum competition would be associated with the tendency to perceive mixed-race faces as “Blacker” than their objective appearance.Open in a separate windowFig. 1.Study 1 and 2 tasks. (A) Sample morph continuum of faces ranging from 0 to 100% Black in 10% increments. (B) Sample trials of the study 1 task. On each trial, subjects classified the face as “Black” or “White (n = 70). (C) Sample trial of the study 2 task. On each trial, a prime word (negative, neutral, or scarcity-related) was followed by a face, which was classified by subjects as “Black” or “White.”To obtain a precise index of perceptual bias, subjects’ responses were fit to a cumulative normal curve, permitting computation of each subject’s point of subjective equality (PSE)—the point at which a face was equally likely to be categorized as Black or White (Methods). A PSE of 0.5 indicates that a face was perceived in accordance with its objective racial content, with 50% Black/50% White morphs being viewed as Black (vs. White) 50% of the time. A PSE below 0.5 indicates that faces were viewed as Black even though they contained less than 50% Black face content. In study 1, subjects’ mean PSE score was 0.47 (SD 0.09), significantly lower than 0.5 [t(69) = −2.71, P < 0.01], indicating that, on average, faces were viewed as Black if they contained 47% or more Black face content. More importantly, lower PSE scores were predicted by subjects’ zero-sum beliefs about competition between Blacks and Whites: those with stronger zero-sum beliefs perceived mixed-race faces as “Blacker” than their objective Black face content [r(70) = −0.28, P = 0.02].Although study 1 provided initial support for our hypothesis using an individual differences approach, the observed effect of zero-sum belief is likely associated with related individual difference constructs, such as subjects’ racial attitudes and social dominance orientation. To test the causal effects of scarcity directly, we conducted a subsequent experiment in which perceptions of scarcity were manipulated. In study 2, 63 subjects completed a race identification task similar to that of study 1, but faces ranged from 100% Black to 100% White at 25% increments. Scarcity was manipulated nonconsciously, with subjects randomly assigned to one of three priming conditions. During the race identification task, word primes representing either scarcity (e.g., scarce), neutral concepts (e.g., fluffy), or negative concepts unrelated to scarcity (e.g., brutal) were presented for 20 ms before each face onset (Fig. 1C). We tested the effect of these prime conditions on subjects’ tendency to perceive mixed-race faces as “Black.”Subjects’ mean PSE score was 0.40 (SD 0.09), significantly lower than objective equality (0.50) [t(62) = −9.33, P < 0.001], indicating that, on average, faces were viewed as Black if they contained as little as 40% Black face content. More importantly, ANOVA indicated a significant effect of priming condition on PSE [F(2,60) = 4.70, P = 0.01], such that scarcity-primed subjects perceived mixed-race faces as significantly “Blacker” (M_PSE = 0.35, SD 0.09) than subjects primed with neutral (M_PSE = 0.41, SD 0.07; P = 0.02) or unrelated negative words (M_PSE = 0.43, SD 0.08; P < 0.01) (Fig. 2). Importantly, negative words did not significantly differ from neutral words (P = 0.89). These results demonstrated that scarcity, but not general negativity, shifted subjects’ perceptual threshold for race.Open in a separate windowFig. 2.Study 2 results (n = 63). PSE scores were significantly lower for subjects in the scarcity condition than those in the negative and neutral conditions. Error bars represent between-subject ±1 SE.Together, studies 1 and 2 supported the notion that economic scarcity induces people to see mixed-race faces as “Blacker” than their objective racial content. To further probe whether scarcity alters one’s internal mental representation of race, we conducted a third experiment assessing whether people spontaneously imagine Black people as appearing “Blacker” when resources are perceived to be scarce.In study 3, 62 subjects were recruited to play a money allocation game in which they were (ostensibly) randomly chosen to be either an allocator or recipient of funds. All subjects were assigned the role of allocator. Subjects then learned they would be given an endowment of money from which to allocate to their partner (the recipient) and that the endowment size would be determined randomly. All subjects were assigned to allocate $10. In the scarcity condition, this amount was presented as $10 out of a possible $100 (a small portion of the total funds); in the control condition it was presented as $10 out of a possible $10 (the maximum portion of the total funds). Pretests confirmed that this manipulation, which varied subjects’ potential allocation amount, was successful in creating the perception of resource scarcity (Methods).While waiting for their partner (the recipient) to come online, subjects were asked to complete “an unrelated task to pretest stimuli for a future face perception study.” In fact, this “pretest” was a reverse correlation image classification procedure designed to assess subjects’ internal visual representations of faces (15, 25). In the task, subjects viewed a series of face pairs depicted as degraded images. In reality, the stimuli used in each trial constituted the same base face overlaid with different patterns of sinusoidal noise to create variation in physiognomy and skin tone (Fig. 3A). Subjects’ task on each of 400 trials was to indicate which face of the pair was “Black” (Fig. 3B). These selections revealed subjects’ mental representations of a Black person, as probed by the subtle distortions created by the different patterns of visual noise on each trial. Thus, images selected as “Black” on each trial were averaged for each subject and then averaged within condition, rendering two composite face images: one representing a Black person under manipulated scarcity, and the other representing a Black person in the control condition (Fig. 4A) (Methods).Open in a separate windowFig. 3.Study 3 task. (A) Patterns of sinusoidal noise and their inverse were added to a single base face (morph of 100 White and 100 Black faces) to create pairs of unique stimuli. (B) Subjects viewed 400 face pairs and, for each pair, indicated which of the two faces was Black.Open in a separate windowFig. 4.Study 3 results (n = 62). (A) Composite image results of face representations created in scarcity and control conditions. (B) Ratings by independent judges (n = 31) indicated the face created under scarcity was darker and more stereotypically Black than the control face. Error bars represent within-subject ±1 SE.Next we presented these composite images to a new sample of 31 subjects, naïve to the conditions under which the faces were created. These subjects were asked to judge the images objectively in terms of their skin tone (from “Extremely light” to “Extremely dark”) and Black stereotypicality (from “Not at all stereotypical” to “Extremely stereotypical”) along 100-point scales. The task was described as a study on the perception of degraded images. As expected, the composite face produced under scarcity was judged as significantly darker [M =71.81, SD 17.31; t(28) = 4.98, P < 0.001] and more stereotypically Black [M = 72.16, SD 25.04; t(28) = 4.67, P < 0.001] than the composite produced in the control condition (M = 52.58, SD 19.23, and M = 50.26, SD = 22.82, respectively; Fig. 4B). This effect was stark, with the clear majority of subjects rating the scarcity face as darker (81%) and more stereotypically Black (77%). Interestingly, however, an objective analysis of image luminance of the individual classification images created in study 3 did not reveal an effect of condition; mean grayscale pixel intensity (from 0 = Black to 255 = White) did not differ between faces created in the scarcity (M = 127.63, SD 5.93) and control conditions [M = 129.04, SD 7.18; F(1,61) = 0.72, P = 0.40], suggesting that the difference in reported skin tone may reflect the particular patterns of contrast represented in resultant facial features.These results demonstrated that, compared with a control condition, perceived scarcity elicited internal mental representations of Black people as “Blacker”—a distortion that, given past research (21–24), should facilitate discrimination.In a final experiment, we tested whether the manipulated effect of scarcity on Black face representations would elicit disparities in resource allocation. In study 4, conducted in a public community setting, 59 subjects were told that “people often make important decisions about others based on very little information” and that we were interested in how a person’s deservingness can be discerned from appearance alone. Subjects viewed the scarcity and control faces created in study 3, side by side, and indicated how they would divide $15 (in whole dollars) between them. Concepts related to scarcity, the economy, or race were not mentioned. Supporting our prediction, subjects allocated significantly less money to the person depicted by the face visualized under scarcity in study 3 (M = $7.16, SD $0.94) than the control face [M = $7.84, SD $0.94; t(58) = 2.77, P < 0.01] (Fig. 5A). Although the dollar amounts offered to each recipient revealed that most subjects attempted to be egalitarian, when faced with a decision point, subjects consistently allocated against the Black face created under scarcity (Fig. 5B). In this way, subtle perceptual effects can have significant consequences. Importantly, because these face representations reflected the experimental manipulation of scarcity, this pattern revealed a causal process whereby scarcity led subjects to view Black faces as “Blacker,” which in turn led to a disparity in money allocation (i.e., an experimental test of mediation).Open in a separate windowFig. 5.Study 4 results (n = 59). (A) A second independent sample allocated fewer resources to the face created in the scarcity vs. control condition. Error bars represent within-subject ± 1 SE. (B) Although allocations centered around $7/$8 divisions, the majority of subjects allocated less money to the Black face created under scarcity.Together, our results provide strong converging evidence for the role of perceptual bias as a mechanism through which economic scarcity enhances discrimination and contributes to racial disparities. Studies 1 and 2 demonstrated that perceptions of scarcity, whether based on one’s economic beliefs or manipulated nonconsciously, increased subjects’ tendency to view mixed-race faces as “Blacker.” Studies 3 and 4 revealed that when resources were framed as scarce (versus neutral), decision makers’ mental image of African American faces became “Blacker,” and this perceptual shift was sufficient to cause a disparity in the allocation of resources. These findings demonstrate that socioeconomic context can shape perceptions of minority racial group members, and this process may contribute to the widening of racial disparities during economic stress.It is well known that the fabric of society begins to fray under conditions of economic scarcity (3, 26). Our findings suggest a motivated perception account for this effect that may complement prior structural explanations. Classic research on intergroup relations has established that competition over resources incites strong motivations to favor the ingroup while derogating outgroups (7, 8). Although we did not manipulate motivation directly, our results are consistent with this account, such that scarcity motivates perceivers to exaggerate the Afrocentric appearance of an African American face, which in turn supports the goal of distributing resources in favor of one’s own group.It is notable that scarcity may be threatening to a perceiver and that the observed effects of scarcity on race perception may have involved a form of threat processing. Indeed, classic research shows that economic competition between groups can lead an individual to perceive outgroup members as more threatening, which in turn evokes prejudice and discrimination (7, 8). More recent research has shown that perceived threats to the self (e.g., vulnerability to personal harm) induced subjects to judge a range of ambiguous social stimuli (e.g., voices, point-light walkers, and biracial faces) as more likely to be African American than European American (27). Although the theoretical question guiding our research concerned effects of scarcity in the context of economic disparities, findings such as these suggest that threat processing might constitute a key process through which situation-based scarcity influences the perceptual processing of race. The results of study 2 indicate that domain-general threat concepts did not bias race perception (relative to neutral concepts), yet it remains possible that, within the context of scarcity, threat may drive this effect.Our findings also dovetail with recent evidence that scarcity is cognitively taxing (28–30) and thus may undermine an individual’s ability to regulate unintended prejudices. Despite egalitarian beliefs, most Americans possess implicit negative associations with minority groups that are kept in check through effortful cognitive control (31, 32). An impairment of control under scarcity could further compound the effects observed in the present research by impairing a perceiver’s ability to control the expression of bias in behavior. It is notable, however, that the effects of scarcity on race perception in the present research occurred implicitly (i.e., through nonconscious priming in study 2 and a very subtle between-subjects manipulation of scarcity in study 3), and thus it is unlikely that the observed effects were driven by changes in cognitive control. Nevertheless, cognitive impairment under scarcity could combine with the observed shift in race perception to create a potent impetus for behaviors that bolster existing racial and ethnic disparities.Our main finding—that scarcity alters the visual perception of African Americans in a way that promotes disparities—issues a new challenge to efforts aimed at reducing discrimination. Although scarcity has been shown to affect explicit decisions about an individuals’ group membership (12, 13), our finding that scarcity-elicited perceptual biases operate implicitly suggests that such biases are particularly resistant to detection and, consequently, regulation. These findings point to the need for a new class of proactive intervention strategies that prevent perceptual biases from forming in the first place, as well as stronger institutional protections that prevent the prejudices evoked by perceptual biases from influencing behavior.In the wake of the 2008 global recession, research on scarcity has taken on renewed urgency, and recent findings confirm that the destabilizing effects of scarcity on society are much more pervasive, and thus pernicious, than the immediate concerns of financial markets. Our research offers a unique psychological perspective to the growing contemporary discourse on the effects of scarcity and income inequality. By showing that scarcity effects on racial disparities operate, at least in part, through malleable perceptions of race, our results reveal new opportunities for changing intergroup perceptions and reducing disparities that are often thought to be products of an unyielding societal structure.     

Three-dimensional lip morphology in skeletal Class I malocclusion with labial inclination of the upper central incisors

PurposeThe purpose of the present study was to examine the three-dimensional (3D) lip morphology in cases of skeletal Class I malocclusion with labial inclination of the upper central incisors.Materials and methodsThirty-five Japanese patients with malocclusion were divided into 2 groups: 20 patients (Test group; 9 males and 11 females; 7 years 5 months–14 years 2 months) who exhibited Class I malocclusion with labial inclination of the upper central incisors and 15 patients (Control group; 7 males and 8 females; 8 years 0 month–14 years 4 months) who exhibited skeletal Class I malocclusion with standard inclination of the upper central incisors. The 3D morphology of the facial soft tissue was recorded using a 3D surface-imaging device for both groups. The differences in the lip morphology variables between the Test and Control groups were then analyzed statistically.ResultsThe central, right and left upper lip inclination angle in the lateral and three-quarter views in the Test group were significantly larger than those in the Control group. The upper lip base area, protrusion surface area, protrusion volume, and protrusion depth were significantly increased compared with the Control group, as were also the lower lip protrusion volume and depth. However, no significant differences in the lower lip base area and surface area were determined between the Test and Control groups.ConclusionsThe upper lip wholly showed labial inclination and forward protrusion in Class I malocclusion with labial inclination of the upper central incisors.     

不同颌位记录方法对全口义齿再修复患者咀嚼效率的影响

目的比较3种记录颌位关系方法对全口义齿再修复患者不同时期咀嚼效率的影响。方法随机选择20名全口义齿再修复患者采取自身对照的方法,每位患者分别采用直接咬合法、哥特式弓描记法、哥特式弓联合面弓转移颌位关系法制作3副全口义齿,并比较不同方法下制作的义齿在患者即刻佩戴义齿时、佩戴义齿3个月后的咀嚼效率的差异。结果患者即刻佩戴义齿时咀嚼效率测定结果显示,使用哥特式弓联合面弓转移颌位关系法制作全口义齿的患者咀嚼效率明显高于使用其他2种方法制作全口义齿的患者（P〈0．05）,而使用直接咬合法与哥特式弓描记法制作全口义齿的患者咀嚼效率没有差异;佩戴义齿3个月后,3组患者的咀嚼效率无明显差异。结论使用哥特式弓联合面弓转移颌位关系法可为患者提供更可靠的颌位记录方法,可以提高患者的即刻咀嚼效率,提高患者的满意度和医生的工作效率。