Most objects react in predictable ways when force is applied to them—unless they have “negative mass.” And then they react exactly opposite from what you would expect.

Now University of Rochester researchers have succeeded in creating particles with negative mass in an atomically thin semiconductor, by causing it to interact with confined light in an optical microcavity.

This alone is “interesting and exciting from a physics perspective,” says Nick Vamivakas, an associate professor of quantum optics and quantum physics at Rochester’s Institute of Optics. “But it also turns out the device we’ve created presents a way to generate laser light with an incrementally small amount of power.”

The device, described in Nature Physics, consists of two mirrors that create an optical microcavity, which confines light at different colors of the spectrum depending on how the mirrors are spaced.

Researchers in Vamivakas’ lab, including co-lead authors Sajal Dhara (now with the Indian Institute of Technology) and PhD student Chitraleema Chakraborty, embedded an atomically thin molybdenum diselenide semiconductor in the microcavity.

The semiconductor was placed in such a way that its interaction with the confined light resulted in small particles from the semiconductor—called excitons—combining with photons from the confined light to form polaritons.

“By causing an exciton to give up some of its identity to a photon to create a polariton, we end up with an object that has a negative mass associated with it,” Vamivakas explains. “That’s kind of a mind-bending thing to think about, because if you try to push or pull it, it will go in the opposite direction from what your intuition would tell you.”

Other research groups have been experimenting with similar devices, Vamivakas says, but this is the first device to produce particles with negative mass.

Though applications are “still down the road,” Vamivakas adds, his lab will continue to explore:

• How the device might serve as a substrate for producing lasers. “With the polaritons we’ve created with this device, the prescription for getting a laser to operate is completely different,” Vamivakas says. “The system starts lasing at a much lower energy input” than traditional lasers now in use.
• The physical implications of creating negative mass in the device. “We’re dreaming up ways to apply pushes and pulls—maybe by applying an electrical field across the device—and then studying how these polaritons move around in the device under application of external force.”

The research, funded by the Air Force Research Laboratory, was initiated with funding from Rochester’s University Research Award program, which provides seed money to promising, high-risk projects.

Other coauthors include Gary Wicks, professor of optics; PhD students Liangyu (Claude) Qiu and Kenny Goodfellow in Vamivakas’ Quantum Nanophotonics Group; and PhD student Trevor O’Loughlin, all of the Institute of Optics.

Pancreatic cancer tumors are resistant to most treatments because of their unique density and cell composition. However, in a new Wilmot Cancer Institute study, scientists discovered that a three-drug combination can simultaneously target the cancer cells as well as the other harmful, inflammatory cells within the tumor to improve survival.

The research builds on previous scientific data from the lab of David C. Linehan, and may define a more personalized approach to treating pancreatic cancer. Ultimately, physicians will use information from the pancreas tumor biopsy about volume and predominance of cancer cells and non-cancerous inflammatory cells that impact the immune system, and then plan the best treatment.

“People with pancreatic cancer don’t have 10 years to wait for the next new drug,” said Linehan, a surgical oncologist, director of clinical operations at Wilmot, and the Seymour I. Schwartz Professor and Chair of the Department of Surgery at the Medical Center.

“Our approach is based on evidence that this disease has particular characteristics involving both the tumor and the immune response,” he said, “and we believe that treatment must address all sides of the problem.”

In fact, more than 80 percent of a pancreatic tumor is comprised of cells that are not malignant cancer cells. But many of these non-cancer cells, called tumor-associated macrophages (or TAMs) still play a vital role in promoting cancer by preventing the immune system from attacking the cancer. In addition to TAMs, pancreatic tumors are also comprised of and surrounded by tumor-associated neutrophils (TANs) that further block the immune system when pancreas cancer is present. (The cancer recruits these detrimental “helper” cells, TAMs and TANs, from the bone marrow.)

Patients who have a high number of TAMs and TANs in their biopsy samples have a poorer prognosis. In general, survival odds for pancreatic cancer are dismal and the incidence is rising, fueling an urgent need for improvements in treatment through research.

The objective of the study, which was published in the British medical journal Gut, was to target TAM and TAN with a combination of experimental drugs that would reduce their numbers and allow the body’s own immune defenses to act appropriately and fight the cancer, and to boost the effectiveness of standard chemotherapy. The study was conducted in mice but researchers also performed correlative analyses on human pancreatic tumor samples.

Results showed that targeting TAM and TAN—as well as the cancer cells—improved antitumor immunity and chemotherapy response better than using any single therapy.

Read more here.

Brianna Theobald has joined the Department of History as an assistant professor. She received her PhD at Arizona State University, and from 2015 to 2017 was a Chancellor’s postdoctoral fellow in American Indian studies, at the University of Illinois at Urbana–Champaign. Her dissertation, “‘The Simplest Rules of Motherhood’: Settler Colonialism and the Regulation of American Indian Reproduction, 1910–1976,” focused on the efforts of Crow women to exercise control over birthing practices and motherhood in the face of federal regulations related to Native American reproduction. Her forthcoming book, Reproduction on the Reservation: Federal Indian Policy, Pregnancy, and Childbirth in the Twentieth Century, is under contract with the University of North Carolina Press. The reproductive justice activism she explores in her first book has inspired her ongoing research agenda, which includes a study of the emergence of a “battered women’s movement” and the establishment of domestic violence shelters in urban centers, small towns, and on reservations in the 1970s and 1980s.

Emily Sherwood is the new director of the Digital Scholarship Lab of the River Campus Libraries.

Sherwood comes from Bucknell University where she was the assistant director of Digital Pedagogy and Scholarship. She was also a Council on Library and Information Resources Postdoctoral Fellow in Digital Scholarship.

Her Ph.D. is in English from The City University of New York. She also has an M.A. in Shakespearian Studies from King’s College, London.

A new seven-week program to train University researchers and community members in community-engaged research using community-based participatory research principles (CBPR) offers an introduction to CBPR principles from the foundations, to communication, funding, and sustainability.

The training is offered in February and March and co-facilitated by community partners and University researchers. The program is offered at no cost to participants. Program participants are eligible to apply for Clinical and Translational Science Institute CBPR Pipeline Pilot Awards. The first session is February 6.

The deadline for registration is Friday, February 2. Contact Indrani Singh at indrani_singh@urmc.rochester.edu with questions or class details.

You just received your Notice of Award on your first grant. Now what? A key to maintaining a successful path in research depends on the strategic use of all of your resources, including managing finances, time, and trainees and staff.

Michelle Janelsins, associate professor of surgery, neuroscience, and radiation oncology, and Rusty Elliott, associate professor of microbiology & immunology, will present tips and discuss common and not-so-common issues related to resource management, specifically related to new investigators and junior faculty.

The event, hosted by the Junior Faculty Biomedical Research Association (JFBRA), will be from 4 to 5 p.m. January 24 in URMC CEL #2-7544. Networking with JFBRA members will follow from 5 to 6 p.m.

To register for this session, mail Faculty_Development@urmc.rochester.edu

James Feeks, Optics, “Two-Photon Adaptive Optics Fluorescence Lifetime Imaging Ophthalmoscopy.” 9 a.m. January 22, 2018. 109 Goergen Hall. Advisor: Jennifer Hunt.

Rahman Lavaee Mashhadi, Computer Science, “Profile-Guided Memory Layout: Theory and Practice.” 9:30 a.m. January 25, 2018. 2506 Wegmans Hall. Advisor: Chen Ding.

Thuy-vy Nguyen, Psychology (Social-Personality), “Breaking the Monotony of Solitude: A Self-Determination Theory Perspective.” 10 a.m., January 25, 2018. 366 Meliora. Advisor: Edward Deci. Co-advisor: Richard Ryan.

Today: Center for Integrated Research Computing (CIRC) symposium. Igor Igumenshchev from the Laboratory for Laser Energetics will review some recent results of three-dimensional simulations of direct-drive implosions. Samuel Weisenthal of the Clinical & Translational Science Institute (CTSI) will discuss predictions of acute kidney injury of re-hospitalized patients. 11:30 a.m. to 1 p.m. Wegmans Hall 1400.

Jan. 23: CIRC Winter Boot Camp begins. Helps students, postdocs, research staff, and faculty learn new programming languages and sharpen their computing and data analytics skills. Click here for a list of courses and to register. Space is limited, so register early.

Jan. 24: Managing your first grant. Presented by Michelle Janelsins, associate professor of surgery, neuroscience, and radiation oncology, and Rusty Elliott, associate professor of microbiology & immunology. Hosted by the Junior Faculty Biomedical Research Association. 4 to 5 p.m. URMC CEL #2-7544. To register, mail Faculty_Development@urmc.rochester.edu

Jan. 31: Deadline to apply for Clinical and Translational Science Institute (CTSI) awards to promote research collaboration between faculty, staff, and students from the University and from Research Centers in Minority Institutions (RCMI). For further information, contact Timothy Dye or Ivelisse Rivera. Read more here.

Jan. 31: Deadline to enter the fifth annual America’s Got Regulatory Science Talent Student Competition,  in which students from across the University compete for a chance to present their regulatory science ideas at the Food and Drug Administration (FDA). Additional information, an entry form, and instructions on how to apply are on the America’s Got Regulatory Science Talent web page. Submit entry forms to Scott Steele by January 31, 2018.

Feb. 1: Deadline to submit initial abstracts for Public Health Science (PHS) pilot projects to stimulate new collaborations with PHS faculty. Proposals are being solicited that support collaborative relationships between investigators who do not have a recent history (past 3 years) of joint funding or who want to expand their current collaborative efforts in new directions and for whom the pilot project would be catalytic in their effort to obtain extramural funding. More information can be found at the PHS website.

Feb. 2: Deadline to register for seven-week training program for University researchers and community members in community-engaged research. Contact Indrani Singh at indrani_singh@urmc.rochester.edu with questions or class details.

Feb. 8: “Deserts, Dust, and Iron Fertilization of the North Pacific Ocean: Cause or Consequence of Global Cooling?” Presented by Carmala Garzione, Helen F. and Fred H. Gowen Professor of Earth and Environmental Sciences. Phelps Colloquium Series. 4-5:30 p.m., Feldman Ballroom, Frederick Douglass Commons. Click here to register.

Feb 23: Deadline to apply for University Research Awards. The Request for Proposals and application are available here. Completed applications should be directed to adele.coelho@rochester.edu.

Feb. 23: Deadline to apply for AS&E PumpPrimer II Awards, which provide seed money to stimulate extramural funding for innovative and high-risk projects otherwise difficult to launch. Faculty in Arts & Science should refer questions to Debra Haring, and those in Engineering to Cindy Gary.

March 1: “Doing Better Next Time: Policy Lessons from the Great Recession and Not-So-Great Recovery.” Presented by Narayana Kocherlakota, Lionel W. McKenzie Professor of Economics. Phelps Colloquium Series. 4-5:30 p.m., location TBD. Click here to register.

April 12: “The American Health Paradox: What’s Missing?” Presented by Nancy Bennett, professor of medicine and public health sciences, director of the Center for Community Health, and co-director of the Clinical and Translational Science Institute. Phelps Colloquium Series. 4-5:30 p.m., Helen Wood Hall. Click here to register.