Synthesis, characterization, and antioxidant activity of Zn2+ and Cu2+ coordinated polyhydroxychalcone complexes.

ABSTRACT: Four new metal complexes [Cu(ISO)2], [Cu(BUT)2] and [Zn(ISO)2], [Zn(BUT)2] of the polyhydroxychalcones (isoliquiritigenin and butein) are synthesized, structurally characterized and their antioxidant activity is investigated. The formation of the complexes [Cu(ISO)2] and [Zn(ISO)2] is followed by Job's plot using NMR titration. The resulting compounds are characterized by mass spectrometry, IR spectroscopy, and elemental analysis. Studies on the radical scavenging activity are performed using DPPH as substrate. The results showed that the antioxidant activities of isoliquiritigenin and butein are enhanced after binding to copper or zinc.

Ethyl Lithiodiazoacetate: Extremely Unstable Intermediate Handled Efficiently in Flow.

Ethyl diazoacetate (EDA) is one of the most prominent diazo reagents. It is frequently used in metal-carbene-type reactions. However, EDA can also be used as a nucleophile under base catalysis. Whilst the addition of EDA to aldehydes can be performed using organic bases, the addition of EDA to other carbonyl electrophiles requires the use of organometallics such as lithium diisopropylamide (LDA). The generated ethyl lithiodiazoacetate is highly reactive and decomposes rapidly, even at low temperatures. Herein, we report a continuous flow protocol that overcomes the problems associated with the instantaneous decomposition of ethyl lithiodiazoacetate. The addition of ethyl lithiodiazoacetate to ketones provides direct access to tertiary diazoalcohols in good yields.

Rapid Generation and Safe Use of Carbenes Enabled by a Novel Flow Protocol with In-line IR spectroscopy.

A powerful new continuous process for the formation and use of donor/acceptor-substituted carbenes is described. The safety profile of diazo group transfer on methyl phenylacetate was determined including kinetic studies in batch and in flow using in-line IR analysis. Batch work-up and liquid chromatography were circumvented by developing an optimized liquid/liquid flow separation method providing aryl diazoacetates in high purity. Fast screening of reaction conditions in flow with in-line IR analysis allowed rapid reaction optimization. Finally, a multistep process of diazo group transfer, extraction, separation and subsequent diazo decomposition combined with multiple X-H insertion reactions was established.

Diazo compounds in continuous-flow technology.

Diazo compounds are very versatile reagents in organic chemistry and meet the challenge of selective assembly of structurally complex molecules. Their leaving group is dinitrogen; therefore, they are very clean and atom-efficient reagents. However, diazo compounds are potentially explosive and extremely difficult to handle on an industrial scale. In this review, it is discussed how continuous flow technology can help to make these powerful reagents accessible on large scale. Microstructured devices can improve heat transfer greatly and help with the handling of dangerous reagents safely. The in situ formation and subsequent consumption of diazo compounds are discussed along with advances in handling diazomethane and ethyl diazoacetate. The potential large-scale applications of a given methodology is emphasized.

Characteristics of homicide followed by suicide incidents in multiple states, 2003-04.

OBJECTIVE: To calculate the prevalence of homicide followed by suicide (homicide/suicide) and provide contextual information on the incidents and demographic information about the individuals involved using data from a surveillance system that is uniquely equipped to study homicide/suicide. METHODS: Data are from the National Violent Death Reporting System (NVDRS). This active state-based surveillance system includes data from seven states for 2003 and 13 states for 2004. The incident-level structure facilitates identification of homicide/suicide incidents. RESULTS: Within participating states, 65 homicide/suicide incidents (homicide rate = 0.230/100,000) occurred in 2003 and 144 incidents (homicide rate = 0.238/100,000) occurred in 2004. Most victims (58%) were a current or former intimate partner of the perpetrator. Among all male perpetrators of intimate partner homicide 30.6% were also suicides. A substantial proportion of the victims (13.7%) were the children of the perpetrator. Overall, most victims (74.6%) were female and most perpetrators were male (91.9%). A recent history of legal problems (25.3%), or financial problems (9.3%) was common among the perpetrators. CONCLUSIONS: The results support earlier research documenting the importance of intimate partner violence (IPV) and situational stressors on homicide/suicide. These results suggest that efforts to provide assistance to families in crisis and enhance the safety of IPV victims are needed to reduce risk for homicide/suicide. The consistency of the results from the NVDRS with those from past studies and the comprehensive information available in the NVDRS highlight the promise of this system for studying homicide/suicide incidents and for evaluating the impact of prevention policies and programs.

School-associated violent deaths in the United States, 1994-1999.

CONTEXT: Despite the public alarm following a series of high-profile school shootings that occurred in the United States during the late 1990s, little is known about the actual incidence and characteristics of school-associated violent deaths. OBJECTIVE: To describe recent trends and features of school-associated violent deaths in the United States. DESIGN, SETTING, AND SUBJECTS: Population-based surveillance study of data collected from media databases, state and local agencies, and police and school officials for July 1, 1994, through June 30, 1999. A case was defined as a homicide, suicide, legal intervention, or unintentional firearm-related death of a student or nonstudent in which the fatal injury occurred (1) on the campus of a public or private elementary or secondary school, (2) while the victim was on the way to or from such a school, or (3) while the victim was attending or traveling to or from an official school-sponsored event. MAIN OUTCOME MEASURES: National estimates of risk of school-associated violent death; national trends in school-associated violent deaths; common features of these events; and potential risk factors for perpetration and victimization. RESULTS: Between 1994 and 1999, 220 events resulting in 253 deaths were identified; 202 events involved 1 death and 18 involved multiple deaths (median, 2 deaths per multiple-victim event). Of the 220 events, 172 were homicides, 30 were suicides, 11 were homicide-suicides, 5 were legal intervention deaths, and 2 were unintentional firearm-related deaths. Students accounted for 172 (68.0%) of these deaths, resulting in an estimated average annual incidence of 0.068 per 100 000 students. Between 1992 and 1999, the rate of single-victim student homicides decreased significantly (P =.03); however, homicide rates for students killed in multiple-victim events increased (P =.047). Most events occurred around the start of the school day, the lunch period, or the end of the school day. For 120 (54.5%) of the incidents, respondents reported that a note, threat, or other action potentially indicating risk for violence occurred prior to the event. Homicide offenders were more likely than homicide victims to have expressed some form of suicidal behavior prior to the event (odds ratio [OR], 6.96; 95% confidence interval [CI], 1.96-24.65) and been bullied by their peers (OR, 2.57; 95% CI, 1.12-5.92). CONCLUSIONS: Although school-associated violent deaths remain rare events, they have occurred often enough to allow for the detection of patterns and the identification of potential risk factors. This information may help schools respond to this problem.

Short-term stability and prospective correlates of bullying in middle-school students: an examination of potential demographic, psychosocial, and environmental influences.

Stability and change of bullying over a four-month interval was examined in 516 middle school students (grades 6-8). The stability coefficient was .65 for the entire sample. There was a significant increase in bullying behavior from Time 1 to Time 2 for 6th grade students; no significant change in bullying was found among 7th or 8th graders. For 6th graders, a greater confidence in using non-violent strategies was associated with less bullying at Time 2, while beliefs supportive of violence and misconduct, less positive adult influences, and more negative peer influences were associated with greater likelihood of bullying at Time 2. Higher levels of impulsivity, anger, and depression were also associated with greater levels of bullying over time. Several explanations for the increase in bullying behaviors among 6th graders are discussed and linked to intervention efforts.

Attitudinal acceptance of intimate partner violence among U.S. adults.

Attitudinal acceptance of intimate partner violence (IPV) is an important correlate of violent behavior. This study examined acceptance of IPV using data collected from a nationally representative telephone survey of 5,238 adults. Multivariable logistic regression analyses were used to test for associations between sociodemographic characteristics, exposure to violence, question order, and acceptance of hitting a spouse or boyfriend/girlfriend under specific circumstances. Depending on the circumstance examined, acceptance of IPV was significantly higher among participants who were male and younger than 35; were non-White; were divorced, separated, or had never married; had not completed high school; had a low household income; or were victims of violence within the past 12 months. Participants were more accepting of women hitting men; they also were consistently more likely to report tolerance of IPV if they were asked first about women hitting men rather than men hitting women. Reports of IPV tolerance need to be interpreted within the context of the survey. Efforts to change IPV attitudes can be tailored to specific IPV circumstances and subgroups, and these efforts should emphasize that the use of physical violence is unacceptable to both genders.

The prevention of youth violence. The rationale for and characteristics of four evaluation projects.

In response to the magnitude of violence in the United States, a number of violence-prevention programs have been implemented throughout the country. However, relatively few have been rigorously evaluated for effectiveness. To encourage development and evaluation of violence-prevention interventions that focus on young children and their families, the Centers for Disease Control and Prevention (CDC) provided funding to four projects in 1996. This paper briefly describes the rationale for funding these projects, which is based on our understanding of the development of aggressive and violent behavior and on the literature regarding promising approaches to prevent problem behavior in this age group. We provide an overview of the four specific projects funded by the CDC as well as a short discussion of some of the many challenges encountered during their implementation.

The influence of geographic mobility on nearly lethal suicide attempts.

Teenagers and young adults are very mobile and mobility has been identified as a potential risk factor for suicidal behavior. We conducted a population-based, case-control study of nearly lethal suicide attempts with 153 cases and 513 controls. Study participants were asked about changing residence over the past 12 months. Results indicate that moving in the past 12 months is positively associated with a nearly lethal suicide attempt (adjusted odds ratio of 2.1, with 95% confidence interval of 1.4-3.3), as are specific characteristics of the move (e.g., frequency, recency, distance, and difficulty staying in touch). These findings confirm and extend prior ecologic research by demonstrating a relationship, at the individual level, between the geographic mobility of adolescents and young adults and nearly lethal suicide attempts.

Medical conditions and nearly lethal suicide attempts.

Physical illness has been studied as a risk factor for suicidal behavior, but little is known about this relationship among younger persons. We conducted a population-based, case-control study in Houston, Texas, from November 1992 through September 1995. The final sample consisted of 153 case- and 513 control-subjects aged 13 to 34 years. Case patients were identified at hospital emergency departments and met criteria for a nearly lethal suicide attempt. Control subjects were recruited via a random-digit-dial telephone survey. Case patients were more likely than controls to report having any serious medical conditions (crude OR = 3.23; 95% CI = 2.12-4.91). After controlling for age, race/ethnicity, alcoholism, depression, and hopelessness, the adjusted odds ratio for men was 4.76 (95% CI = 1.87-12.17), whereas the adjusted odds ratio for women was 1.60 (95% CI-0.62-4.17), suggesting that young men with medical conditions are at increased risk for nearly lethal suicide attempts. Increased efforts to identify and appropriately refer these patients are needed.

An unmatched case-control study of nearly lethal suicide attempts in Houston, Texas: research methods and measurements.

This article details the research methods and measurements used in conducting a population-based, case-control study of nearly lethal suicide attempts among persons aged 13-34 years, residing in Houston, Texas. From November 1992 to July 1995, we interviewed 153 case subjects presenting at one of three participating hospital emergency departments and used random digit dialing to identify 513 control subjects residing in the same catchment area in which cases were enlisted. Unlike most research in this area, this study was designed to extend our understanding of suicidal behavior and prevention activities beyond identification and treatment of depression and other mental illnesses. We discuss the overall strengths and weaknesses of our study design and conclude that this methodology is well suited for studying rare outcomes such as nearly lethal suicide.

Suicide planning among high school students who report attempting suicide.

Using a nationally representative sample of 16,296 high school students, we examined those who reported attempting suicide but did not report a suicide plan in the past 12 months. Results from logistic regression analyses showed that the 15% of attempters who did not report planning were as likely to receive medical treatment after their attempt as the attempters who did report planning. They also were more likely than nonideators and less likely than attempters who reported planning to report substance use and weapon carrying. All attempters, regardless of planning, were at high risk for fighting. Additional effort is needed to understand and prevent unplanned suicide attempts.

Suicide ideation among US college students. Associations with other injury risk behaviors.

Suicide, the endpoint of a continuum that begins with suicide ideation, is the third leading cause of death among the US college-aged population. The first and second leading causes of death among this age group, unintentional injury and homicide, may also be linked to suicide ideation. We used data from the National College Health Risk Behavior Survey to examine the association between suicide ideation and injury-related behaviors among 18- to 24-year-old college students. Students who reported suicide ideation were significantly more likely than students who did not report considering suicide to carry a weapon, engage in a physical fight, boat or swim after drinking alcohol, ride with a driver who had been drinking alcohol, drive after drinking alcohol, and rarely or never used seat belts. Given this clustering of injury-related risk behaviors, college prevention programs should aim to reduce risks for injuries comprehensively, rather than addressing each risk behavior separately.

Trends in suicide ideation and suicidal behavior among high school students in the United States, 1991-1997.

To examine trends in suicide ideation and behavior over time, the authors analyze data from nationally representative samples of between 10,904 and 16,296 students participating in the 1991, 1993, 1995, and 1997 Youth Risk Behavior Surveys. These data describe the proportion of United States students in grades 9 through 12 that reported having (1) seriously considered attempting suicide, (2) made a plan to attempt suicide, (3) attempted suicide, and (4) made an injurious suicide attempt. From 1991 to 1997, the percentage of students seriously considering suicide and the percentage that made a suicide plan showed significant linear decreases. However, the percentage of students that made an injurious suicide attempt showed a significant linear increase. These trends make it unlikely that relevant national health objectives for the year 2000 will be met. Additional efforts are needed to identify and disseminate strategies that effectively reduce suicidal thoughts and behaviors among adolescents.

The role of families and care givers as risk and protective factors in preventing youth violence.

This paper reviews research which discusses the risk and protective functions that families and other caregivers provide in influencing the development of aggressive behavior in youth. Currently, there is an emphasis on providing violence prevention programs in the school environment, typically with little parental or caregiver involvement. By enhancing the role of families and caregivers in youth violence prevention programs, we assert that an unique opportunity exists to both address specific risk factors for violence while enhancing the protective features of the family. Relatedly, the risk literature on youth violence indicates that the most influential risk factors (i.e., the family, community, and peers) have their principle impact on youth aggression outside the school. We suggest a shift in the focus of violence prevention programming that is more inclusive of families as both a risk and protective agent. In support of this position, relevant theory and reviews of exemplary family-involved programs are offered. Challenges to involving youth caregivers are identified and recommendations for overcoming those challenges suggested. Last, recommendations for future research and public policy in the prevention of youth violence are offered.

Recent trends in violence-related behaviors among high school students in the United States.

CONTEXT: Violence-related behaviors such as fighting and weapon carrying are associated with serious physical and psychosocial consequences for adolescents. OBJECTIVE: To measure trends in nonfatal violent behaviors among adolescents in the United States between 1991 and 1997. DESIGN, SETTING, AND PARTICIPANTS: Nationally representative data from the 1991, 1993, 1995, and 1997 Youth Risk Behavior Surveys were analyzed to describe the percentage of students in grades 9 through 12 who engaged in behaviors related to violence. Overall response rates for each of these years were 68%, 70%, 60%, and 69%, respectively. To assess the statistical significance of time trends for these variables, logistic regression analyses were conducted that controlled for sex, grade, and race or ethnicity and simultaneously assessed linear and higher-order effects. MAIN OUTCOME MEASURES: Self-reported weapon carrying, physical fighting, fighting-related injuries, feeling unsafe, and damaged or stolen property. RESULTS: Between 1991 and 1997, the percentage of students in a physical fight decreased 14%, from 42.5% (95% confidence interval [CI], 40.1%-44.9%) to 36.6% (95% CI, 34.6%-38.6%); the percentage of students injured in a physical fight decreased 20%, from 4.4% (95% CI, 3.6%-5.2%) to 3.5% (95% CI, 2.9%-4.1%); and the percentage of students who carried a weapon decreased 30%, from 26.1% (95% CI, 23.8%-28.4%) to 18.3% (95% CI, 16.5%-20.1%). Between 1993 and 1997, the percentage of students who carried a gun decreased 25%, from 7.9% (95% CI, 6.6%-9.2%) to 5.9% (95% CI, 5.1%-6.7%); the percentage of students in a physical fight on school property decreased 9%, from 16.2% (95% CI, 15.0%-17.4%) to 14.8% (95% CI, 13.5%-16.1 %); and the percentage of students who carried a weapon on school property decreased 28%, from 11.8% (95% CI, 10.4%-13.2%) to 8.5% (95% CI, 7.0%-10.0%). All of these changes represent significant linear decreases. CONCLUSIONS: Declines in fighting and weapon carrying among US adolescents between 1991 and 1997 are encouraging and consistent with declines in homicide, nonfatal victimization, and school crime rates. Further research should explore why behaviors related to interpersonal violence are decreasing and what types of interventions are most effective.

Epidemiology of injuries among women after physical assaults: the role of self-protective behaviors.

Physical assaults against women result in more than 5,000 deaths and 1 million nonfatal injuries per year in the United States. Data from the National Crime Victimization Survey, 1992-1995, were used to test the association between injury risk and self-protective behaviors, while controlling for victim, offender, and crime-related characteristics. Unlike in prior studies, a self-protective behavior measure that accounted for the temporal sequencing of the occurrence of injuries and self-protective behaviors was used. The study also examined whether the effect of self-protective behaviors varied as a function of victim-offender relationship status. The sample included 3,206 incidents in which females were physically assaulted by a lone male offender within the previous 6 months. Multivariate results revealed that women who used self-protective measures were less likely to be injured than were women who did not use self-protective measures or who did so only after being injured. The effect of self-protective behaviors on risk of injury did not vary as a function of the victim-offender relationship. The inverse association found between self-protective behaviors and injury risk differs from those of previous studies. Owing to inconsistent findings across studies, caution should be used when making recommendations to women regarding whether or not they should use self-protective behaviors during a physical assault.

Neurotoxicity in single photon emission computed tomography brain scans of patients reporting chemical sensitivities.

The subset of patients reporting chemical sensitivity with neurocognitive complaints usually exhibits specific abnormalities of brain metabolism consistent with neurotoxicity, on imaging with single photon emission computed tomography (SPECT). These recurrent neurotoxic patterns are characterized by a mismatch in tracer uptake between early- and late-phase imaging, multiple hot and cold foci throughout the cortex, temporal asymmetry and increased tracer uptake into the soft tissues and, sometimes, the basal ganglia. Previous studies confirm these neurotoxic findings in patients with neurotoxic chemical exposures and breast implants. Affective processes such as depression do not, alone, show this pattern. These abnormalities in SPECT images correlate with documented neurocognitive impairment. Controlled challenges to ambient chemicals can induce profound neurotoxic changes seen on SPECT imaging in chemically sensitive patients. Detoxification treatment techniques frequently produce significant improvement on brain SPECT brain imaging in these patients. Neurotoxicity appears to be characteristic in many cases of chemical sensitivity.