Publications by authors named "Muhammad Zahir"

22 Publications

  • Page 1 of 1

Ancient proteins provide evidence of dairy consumption in eastern Africa.

Nat Commun 2021 01 27;12(1):632. Epub 2021 Jan 27.

Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany.

Consuming the milk of other species is a unique adaptation of Homo sapiens, with implications for health, birth spacing and evolution. Key questions nonetheless remain regarding the origins of dairying and its relationship to the genetically-determined ability to drink milk into adulthood through lactase persistence (LP). As a major centre of LP diversity, Africa is of significant interest to the evolution of dairying. Here we report proteomic evidence for milk consumption in ancient Africa. Using liquid chromatography tandem mass spectrometry (LC-MS/MS) we identify dairy proteins in human dental calculus from northeastern Africa, directly demonstrating milk consumption at least six millennia ago. Our findings indicate that pastoralist groups were drinking milk as soon as herding spread into eastern Africa, at a time when the genetic adaptation for milk digestion was absent or rare. Our study links LP status in specific ancient individuals with direct evidence for their consumption of dairy products.
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http://dx.doi.org/10.1038/s41467-020-20682-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7841170PMC
January 2021

Copper-doped induced ferromagnetic half-metal zirconium diselenide single crystals.

Nanotechnology 2020 Mar 4;31(23):235704. Epub 2020 Feb 4.

College of Physics and Optoelectronic Engineering, Shenzhen University, Nanhai Ave. 3688, Shenzhen, Guangdong 518060, People's Republic of China.

Two-dimensional (2D) magnetic layered materials have attracted considerable attention in memory storage devices due to their exciting magnetic ordering. Herein, the electronic and magnetic properties of high-quality single crystals zirconium diselenide and copper (Cu)-doped zirconium diselenide as grown via chemical vapor transport technique combined with first principle density functional theory calculations were investigated. A semimetallic state is recognized for CuZrSe as measured through resistance versus temperature measurements and angle resolved photoemission spectroscopy (ARPES). The magnetic measurement shows diamagnetic semiconducting behaviour for ZrSe, whereas CuZrSe exhibits ferromagnetic character via applying perpendicular magnetic field. CuZrSe reveals the room temperature magnetic moment ∼0.0125 emu g, while the Curie temperature is ∼363.49 K. Furthermore, first principle density functional theory (DFT) calculations show energetically long range ferromagnetic ordering in a half-metallic Cu-doped ZrSe, while a diamagnetic state in case of ZrSe agrees well with experiment results. These results suggest that due to strong interaction elements at the octahedral site of zirconium atoms when replaced by copper atoms, which can change the spin ordering of electrons and make zirconium vacancy, while their magnetic moment is increased. Very importantly the half-metallic character of CuZrSe promotes much spin polarized electrons around the Fermi level, suggesting significant potential in future memory devices and spintronic applications.
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http://dx.doi.org/10.1088/1361-6528/ab72b3DOI Listing
March 2020

Transition from Semimetal to Semiconductor in ZrTe Induced by Se Substitution.

ACS Nano 2020 Jan 24;14(1):835-841. Epub 2019 Dec 24.

National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Strongly coupled Quantum Matter Physics , University of Science and Technology of China , Hefei 230029 , China.

Two-dimensional layered transition-metal telluride can build stable metallic, metastable metallic, or semimetallic polymorphic crystal structures with enormous technological and scientific applications. Herein the hexagonal structures of zirconium ditelluride (ZrTe) and ZrTeSe (0 ≤ ≤ 1) single crystals were selectively synthesized through the chemical vapor transport method. The electronic band structures were systematically studied through angle-resolved photoemission spectroscopy (ARPES) combined with first-principles density functional theory (DFT) calculations. The ARPES results suggested a clear electronic phase transition from a semimetal to a semiconductor in ZrTeSe with the value changing. Compared with pristine ZrTe, the valence band splitting in ZrTeSe decreased at the Γ point due to the reduction of the spin-orbit interaction, whereas an indirect band gap opened in the vicinity of the Fermi level with the increase in Se concentration. Our DFT calculations further confirmed that the substituted Se atoms on Te sites could affect the band structure of ZrTe to induce a distinct transition from semimetal to semiconductor, suggesting their high potential for valleytronics applications.
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http://dx.doi.org/10.1021/acsnano.9b07931DOI Listing
January 2020

The formation of human populations in South and Central Asia.

Authors:
Vagheesh M Narasimhan Nick Patterson Priya Moorjani Nadin Rohland Rebecca Bernardos Swapan Mallick Iosif Lazaridis Nathan Nakatsuka Iñigo Olalde Mark Lipson Alexander M Kim Luca M Olivieri Alfredo Coppa Massimo Vidale James Mallory Vyacheslav Moiseyev Egor Kitov Janet Monge Nicole Adamski Neel Alex Nasreen Broomandkhoshbacht Francesca Candilio Kimberly Callan Olivia Cheronet Brendan J Culleton Matthew Ferry Daniel Fernandes Suzanne Freilich Beatriz Gamarra Daniel Gaudio Mateja Hajdinjak Éadaoin Harney Thomas K Harper Denise Keating Ann Marie Lawson Matthew Mah Kirsten Mandl Megan Michel Mario Novak Jonas Oppenheimer Niraj Rai Kendra Sirak Viviane Slon Kristin Stewardson Fatma Zalzala Zhao Zhang Gaziz Akhatov Anatoly N Bagashev Alessandra Bagnera Bauryzhan Baitanayev Julio Bendezu-Sarmiento Arman A Bissembaev Gian Luca Bonora Temirlan T Chargynov Tatiana Chikisheva Petr K Dashkovskiy Anatoly Derevianko Miroslav Dobeš Katerina Douka Nadezhda Dubova Meiram N Duisengali Dmitry Enshin Andrey Epimakhov Alexey V Fribus Dorian Fuller Alexander Goryachev Andrey Gromov Sergey P Grushin Bryan Hanks Margaret Judd Erlan Kazizov Aleksander Khokhlov Aleksander P Krygin Elena Kupriyanova Pavel Kuznetsov Donata Luiselli Farhod Maksudov Aslan M Mamedov Talgat B Mamirov Christopher Meiklejohn Deborah C Merrett Roberto Micheli Oleg Mochalov Samariddin Mustafokulov Ayushi Nayak Davide Pettener Richard Potts Dmitry Razhev Marina Rykun Stefania Sarno Tatyana M Savenkova Kulyan Sikhymbaeva Sergey M Slepchenko Oroz A Soltobaev Nadezhda Stepanova Svetlana Svyatko Kubatbek Tabaldiev Maria Teschler-Nicola Alexey A Tishkin Vitaly V Tkachev Sergey Vasilyev Petr Velemínský Dmitriy Voyakin Antonina Yermolayeva Muhammad Zahir Valery S Zubkov Alisa Zubova Vasant S Shinde Carles Lalueza-Fox Matthias Meyer David Anthony Nicole Boivin Kumarasamy Thangaraj Douglas J Kennett Michael Frachetti Ron Pinhasi David Reich

Science 2019 09;365(6457)

Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.

By sequencing 523 ancient humans, we show that the primary source of ancestry in modern South Asians is a prehistoric genetic gradient between people related to early hunter-gatherers of Iran and Southeast Asia. After the Indus Valley Civilization's decline, its people mixed with individuals in the southeast to form one of the two main ancestral populations of South Asia, whose direct descendants live in southern India. Simultaneously, they mixed with descendants of Steppe pastoralists who, starting around 4000 years ago, spread via Central Asia to form the other main ancestral population. The Steppe ancestry in South Asia has the same profile as that in Bronze Age Eastern Europe, tracking a movement of people that affected both regions and that likely spread the distinctive features shared between Indo-Iranian and Balto-Slavic languages.
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http://dx.doi.org/10.1126/science.aat7487DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6822619PMC
September 2019

Archaeological assessment reveals Earth's early transformation through land use.

Authors:
Lucas Stephens Dorian Fuller Nicole Boivin Torben Rick Nicolas Gauthier Andrea Kay Ben Marwick Chelsey Geralda Armstrong C Michael Barton Tim Denham Kristina Douglass Jonathan Driver Lisa Janz Patrick Roberts J Daniel Rogers Heather Thakar Mark Altaweel Amber L Johnson Maria Marta Sampietro Vattuone Mark Aldenderfer Sonia Archila Gilberto Artioli Martin T Bale Timothy Beach Ferran Borrell Todd Braje Philip I Buckland Nayeli Guadalupe Jiménez Cano José M Capriles Agustín Diez Castillo Çiler Çilingiroğlu Michelle Negus Cleary James Conolly Peter R Coutros R Alan Covey Mauro Cremaschi Alison Crowther Lindsay Der Savino di Lernia John F Doershuk William E Doolittle Kevin J Edwards Jon M Erlandson Damian Evans Andrew Fairbairn Patrick Faulkner Gary Feinman Ricardo Fernandes Scott M Fitzpatrick Ralph Fyfe Elena Garcea Steve Goldstein Reed Charles Goodman Jade Dalpoim Guedes Jason Herrmann Peter Hiscock Peter Hommel K Ann Horsburgh Carrie Hritz John W Ives Aripekka Junno Jennifer G Kahn Brett Kaufman Catherine Kearns Tristram R Kidder François Lanoë Dan Lawrence Gyoung-Ah Lee Maureece J Levin Henrik B Lindskoug José Antonio López-Sáez Scott Macrae Rob Marchant John M Marston Sarah McClure Mark D McCoy Alicia Ventresca Miller Michael Morrison Giedre Motuzaite Matuzeviciute Johannes Müller Ayushi Nayak Sofwan Noerwidi Tanya M Peres Christian E Peterson Lucas Proctor Asa R Randall Steve Renette Gwen Robbins Schug Krysta Ryzewski Rakesh Saini Vivian Scheinsohn Peter Schmidt Pauline Sebillaud Oula Seitsonen Ian A Simpson Arkadiusz Sołtysiak Robert J Speakman Robert N Spengler Martina L Steffen Michael J Storozum Keir M Strickland Jessica Thompson T L Thurston Sean Ulm M Cemre Ustunkaya Martin H Welker Catherine West Patrick Ryan Williams David K Wright Nathan Wright Muhammad Zahir Andrea Zerboni Ella Beaudoin Santiago Munevar Garcia Jeremy Powell Alexa Thornton Jed O Kaplan Marie-José Gaillard Kees Klein Goldewijk Erle Ellis

Science 2019 08;365(6456):897-902

Environmentally transformative human use of land accelerated with the emergence of agriculture, but the extent, trajectory, and implications of these early changes are not well understood. An empirical global assessment of land use from 10,000 years before the present (yr B.P.) to 1850 CE reveals a planet largely transformed by hunter-gatherers, farmers, and pastoralists by 3000 years ago, considerably earlier than the dates in the land-use reconstructions commonly used by Earth scientists. Synthesis of knowledge contributed by more than 250 archaeologists highlighted gaps in archaeological expertise and data quality, which peaked for 2000 yr B.P. and in traditionally studied and wealthier regions. Archaeological reconstruction of global land-use history illuminates the deep roots of Earth's transformation and challenges the emerging Anthropocene paradigm that large-scale anthropogenic global environmental change is mostly a recent phenomenon.
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http://dx.doi.org/10.1126/science.aax1192DOI Listing
August 2019

Single Nickel Atoms on Nitrogen-Doped Graphene Enabling Enhanced Kinetics of Lithium-Sulfur Batteries.

Adv Mater 2019 Oct 18;31(40):e1903955. Epub 2019 Aug 18.

Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin, 300071, P. R. China.

Lithium-sulfur (Li-S) batteries have arousing interest because of their high theoretical energy density. However, they often suffer from sluggish conversion of lithium polysulfides (LiPS) during the charge/discharge process. Single nickel (Ni) atoms on nitrogen-doped graphene (Ni@NG) with Ni-N structure are prepared and introduced to modify the separators of Li-S batteries. The oxidized Ni sites of the Ni-N structure act as polysulfide traps, efficiently accommodating polysulfide ion electrons by forming strong S ⋅⋅⋅NiN bonding. Additionally, charge transfer between the LiPS and oxidized Ni sites endows the LiPS on Ni@NG with low free energy and decomposition energy barrier in an electrochemical process, accelerating the kinetic conversion of LiPS during the charge/discharge process. Furthermore, the large binding energy of LiPS on Ni@NG also shows its ability to immobilize the LiPS and further suppresses the undesirable shuttle effect. Therefore, a Li-S battery based on a Ni@NG modified separator exhibits excellent rate performance and stable cycling life with only 0.06% capacity decay per cycle. It affords fresh insights for developing single-atom catalysts to accelerate the kinetic conversion of LiPS for highly stable Li-S batteries.
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http://dx.doi.org/10.1002/adma.201903955DOI Listing
October 2019

High-temperature quality of accelerated spheroidization on SUP9 leaf spring to enhance machinability.

Heliyon 2018 Dec 26;4(12):e01076. Epub 2018 Dec 26.

Department of Mechanical Engineering, Sriwijaya University, 30662, Indonesia.

The high temperature on the austenitization showed the varied results in the fast spheroidization in high carbon leaf spring steel SUP9/55CrMnA. The heating temperature was held for 15 minutes in the austenitization temperature at 800, 850, and 900 °C respectively, which was intended to break cementite lamellar and then proceed to spheroidization at 720 °C for 2 hours. The purpose of this treatment was to enhance machinability, the experiment results showed a significant enhancing in machinability at 800 °C with 180 VHN hardness value and machining performance increased to 78.5% with 54 seconds machining time. The drilling process used an HSS twist drilling 2.5 mm in diameter and a workpiece height of 15 mm under equal spindle speed and load. The machining process is recommended to know the quality of the cementite, which was revealed on the drilling process of the initial specimen, the drill bit was unable to drill the specimen caused by chisel edge blunted. The acceleration spheroidization process under high temperature showed the significant enhancing in machinability of SUP9 leaf spring.
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http://dx.doi.org/10.1016/j.heliyon.2018.e01076DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307316PMC
December 2018

Magnetic Isotropy/Anisotropy in Layered Metal Phosphorous Trichalcogenide MPS₃ (M = Mn, Fe)Single Crystals.

Micromachines (Basel) 2018 Jun 11;9(6). Epub 2018 Jun 11.

National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China.

Despite the fact that two-dimensional layered magnetic materials hold immense potential applications in the field of spintronic devices, tunable magnetism is still a challenge due to the lack of controllable synthesis. Herein, high-quality single crystals MPS₃ (M= Mn, Fe) of millimeter size were synthesized through the chemical vapor transport method. After systemic structural characterizations, magnetic properties were studied on the bulk MPS₃ layers through experiments, along with first principle theoretical calculations. The susceptibilities as well as the EPR results evidently revealed unique isotropic and anisotropic behavior in MnPS₃ and FePS₃ crystals, respectively. It is worth noting that both of these materials show antiferromagnetic states at measured temperatures. The estimated antiferromagnetic transition temperature is 78 K for bulk MnPS₃ and 123 K for FePS₃ crystals. The spin polarized density functional theory calculations confirmed that the band gap of the antiferromagnetic states could be generated owing to asymmetric response all over the energy range. The ferromagnetic state in MnPS₃ and FePS₃ is less stable as compared to the antiferromagnetic state, resulting in antiferromagnetic behavior. Additionally, frequency-dependent dielectric functions for parallel and perpendicular electric field component vectors, along with the absorption properties of MPS₃, are thoroughly investigated.
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http://dx.doi.org/10.3390/mi9060292DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6187345PMC
June 2018

Plant growth promoting bacteria: role in soil improvement, abiotic and biotic stress management of crops.

Plant Cell Rep 2018 Dec 3;37(12):1599-1609. Epub 2018 Sep 3.

Islamia College University Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan.

Agricultural production-a major contributing factor towards global food supply-is highly reliant on field crops which are under severe threats ranging from poor soil quality, biotic, abiotic stresses and changing climatic conditions. To overcome these challenges, larger exertions are required to boost production of agricultural crops in a defensible mode. Since the evolution of fertilizers and pesticides, global crop productivity has experienced an unprecedented elevation, but at the cost of environmental and ecological unsustainability. To enhance the agricultural outputs in a sustainable way, the novel and eco-friendly strategies must be employed in agriculture, which would lead to reduced use of hazardous chemicals. Thus, the utilization of our knowledge about natural growth stimulators can lead to decrease reliance on fertilizers and pesticide which are widely used for increasing crop productivity. Among beneficial microbes, plant growth promoting bacteria offers excellent opportunities for their wide utilization in agriculture to manage soil quality and other factors which correspond to limited growth and yield output of major field crops. The aim of this review is to examine the potential role of plant growth stimulating bacteria in soil fertility and enabling crops to cope with biotic and abiotic challenges.
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http://dx.doi.org/10.1007/s00299-018-2341-2DOI Listing
December 2018

Exfoliation of ultrathin FePS layers as a promising electrocatalyst for the oxygen evolution reaction.

Chem Commun (Camb) 2018 Apr;54(35):4481-4484

National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China.

Few-layer ternary FePS3 nanosheets, prepared via chemical vapor transport synthesis and ball-milling exfoliation, exhibit excellent electrocatalytic performance for the oxygen evolution reaction in an alkaline medium. Combined with first principles calculations, our X-ray spectroscopy and HRTEM results clearly reveal that the introduction of in-plane defects in FePS3 layers after exfoliation and formation of a FePS3-FeOOH heterostructure during the OER process largely contribute to the catalytic activity enhancement.
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http://dx.doi.org/10.1039/c8cc01076eDOI Listing
April 2018

Homo sapiens in Arabia by 85,000 years ago.

Nat Ecol Evol 2018 05 9;2(5):800-809. Epub 2018 Apr 9.

Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany.

Understanding the timing and character of the expansion of Homo sapiens out of Africa is critical for inferring the colonization and admixture processes that underpin global population history. It has been argued that dispersal out of Africa had an early phase, particularly ~130-90 thousand years ago (ka), that reached only the East Mediterranean Levant, and a later phase, ~60-50 ka, that extended across the diverse environments of Eurasia to Sahul. However, recent findings from East Asia and Sahul challenge this model. Here we show that H. sapiens was in the Arabian Peninsula before 85 ka. We describe the Al Wusta-1 (AW-1) intermediate phalanx from the site of Al Wusta in the Nefud desert, Saudi Arabia. AW-1 is the oldest directly dated fossil of our species outside Africa and the Levant. The palaeoenvironmental context of Al Wusta demonstrates that H. sapiens using Middle Palaeolithic stone tools dispersed into Arabia during a phase of increased precipitation driven by orbital forcing, in association with a primarily African fauna. A Bayesian model incorporating independent chronometric age estimates indicates a chronology for Al Wusta of ~95-86 ka, which we correlate with a humid episode in the later part of Marine Isotope Stage 5 known from various regional records. Al Wusta shows that early dispersals were more spatially and temporally extensive than previously thought. Early H. sapiens dispersals out of Africa were not limited to winter rainfall-fed Levantine Mediterranean woodlands immediately adjacent to Africa, but extended deep into the semi-arid grasslands of Arabia, facilitated by periods of enhanced monsoonal rainfall.
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http://dx.doi.org/10.1038/s41559-018-0518-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5935238PMC
May 2018

Ferromagnetism in CVT grown tungsten diselenide single crystals with nickel doping.

Nanotechnology 2018 Mar;29(11):115701

Two dimensional (2D) single crystal layered transition materials have had extensive consideration owing to their interesting magnetic properties, originating from their lattices and strong spin-orbit coupling, which make them of vital importance for spintronic applications. Herein, we present synthesis of a highly crystalline tungsten diselenide layered single crystal grown by chemical vapor transport technique and doped with nickel (Ni) to tailor its magnetic properties. The pristine WSe single crystal and Ni-doped crystal were characterized and analyzed for magnetic properties using both experimental and computational aspects. It was found that the magnetic behavior of the 2D layered WSe crystal changed from diamagnetic to ferromagnetic after Ni-doping at all tested temperatures. Moreover, first principle density functional theory (DFT) calculations further confirmed the origin of room temperature ferromagnetism of Ni-doped WSe, where the d-orbitals of the doped Ni atom promoted the spin moment and thus largely contributed to the magnetism change in the 2D layered material.
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http://dx.doi.org/10.1088/1361-6528/aaa63eDOI Listing
March 2018

Stable 1T-MoSe and Carbon Nanotube Hybridized Flexible Film: Binder-Free and High-Performance Li-Ion Anode.

ACS Nano 2017 06 6;11(6):6483-6491. Epub 2017 Jun 6.

National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China , Hefei, Anhui 230029, China.

Two-dimensional stable metallic 1T-MoSe with expanded interlayer spacing of 10.0 Å in situ grown on SWCNTs film is fabricated via a one-step solvothermal method. Combined with X-ray absorption near-edge structures, our characterization reveals that such 1T-MoSe and single-walled carbon nanotubes (abbreviated as 1T-MoSe/SWCNTs) hybridized structure can provide strong electrical and chemical coupling between 1T-MoSe nanosheets and SWCNT film in a form of C-O-Mo bonding, which significantly benefits a high-efficiency electron/ion transport pathway and structural stability, thus directly enabling high-performance lithium storage properties. In particular, as a flexible and binder-free Li-ion anode, the 1T-MoSe/SWCNTs electrode exhibits excellent rate capacity, which delivers a capacity of 630 mAh/g at 3000 mA/g. Meanwhile, the strong C-O-Mo bonding of 1T-MoSe/SWCNTs accommodates volume alteration during the repeated charge/discharge process, which gives rise to 89% capacity retention and a capacity of 971 mAh/g at 300 mA/g after 100 cycles. This synthetic route of a multifunctional MoSe/SWCNTs hybrid might be extended to fabricate other 2D layer-based flexible and light electrodes for various applications such as electronics, optics, and catalysts.
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http://dx.doi.org/10.1021/acsnano.7b03329DOI Listing
June 2017

Synthesis of NiS/MoS heterocatalyst for Enhanced Hydrogen Evolution Reaction.

Langmuir 2017 05 16;33(21):5148-5153. Epub 2017 May 16.

National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China , Hefei, Anhui 230029, P.R. China.

We demonstrate a heterostructure NiS/MoS hybrid with tight interface synthesized via an improved hydrothermal method. As compared to pure MoS, the increased surface area and the shorten charge transport pathway in the layered hybrid significantly promote the photocatalytic efficiency for hydrogen evolution reaction (HER). In particularly, the optimized NiS/MoS hybrid with 20 wt % NiS exhibits the highest photocatalytic activity with HER value of 406 μmolgh, which is enhanced by 70% compared to that of pure MoS nanosheets (285.0 μmolgh). Moreover, the value is 4 times more than the commercial MoS (92.0 μmolgh), indicating the high potential of the hybrid in the catalytic fields.
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http://dx.doi.org/10.1021/acs.langmuir.7b00694DOI Listing
May 2017

Incidence of Venous Thromboembolism in cancer patients treated with Cisplatin based chemotherapy - a cohort study.

BMC Cancer 2017 01 16;17(1):57. Epub 2017 Jan 16.

Department of Oncology, Aga Khan University Hospital, Stadium Road, PO BOX: 3500, Karachi, 74800, Pakistan.

Background: Cancer related thrombosis not only increases morbidity and mortality but also poses a significant financial burden on health care system. Risk of venous thromboembolism (VTE) in these patients substantially increases with the addition of chemotherapy. Lately, cisplatin has been implicated as an independent factor. There is little data estimating the risk of venous thromboembolism in patients receiving cisplatin based chemotherapy when compared to other chemotherapeutic agents.

Methods: Patients who had received chemotherapy between November 2010 and October 2012 were retrospectively identified from a single institute cancer registry. 200 patients who had received cisplatin based chemotherapy were identified as the exposed group while 200 patients who had received non-Cisplatin based regimens were identified as the non-exposed group. Patients were followed for development of VTE throughout the entire duration of therapy and one month thereafter. Cox proportional hazard model was used to compute relative risks with 95% confidence intervals.

Results: The baseline characteristics were similar in the two groups. Mean age for the entire cohort was 55.4 ± 10.7 years and male to female ratio was almost 1:1. On univariate analysis, cisplatin based chemotherapy, presence of central venous catheter, female gender, poor performance status, high risk stratification according to the Khorana model and use of granulocyte colony stimulating factor were all significantly associated with the development of VTE. The crude relative risk for the incidence of VTE in cisplatin group was 2.8 (95% CI, 1.4 - 4.2) times compared to the non-Cisplatin group. When the relative risk was adjusted for the above variables in multivariable analysis, it increased to 3.3 (95% CI, 1.6 - 6.8) compared to the control group.

Conclusion: A high incidence of VTE in patients receiving cisplatin based chemotherapy was demonstrated in this study. Prospective studies are warranted to establish this observation with certainty and to explore the possible use of thromboprophylaxis in patients receiving cisplatin based chemotherapeutic regimens.
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http://dx.doi.org/10.1186/s12885-016-3032-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5238519PMC
January 2017

A Ternary Alloy Substrate to Synthesize Monolayer Graphene with Liquid Carbon Precursor.

ACS Nano 2017 02 18;11(2):1371-1379. Epub 2017 Jan 18.

National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China , Hefei, Anhui 230029, PR China.

Here we demonstrate a ternary CuNiZn alloy substrate for controllably synthesizing monolayer graphene using a liquid carbon precursor cyclohexane via a facile CVD route. In contrast with elemental metal or bimetal substrates, the alloy-induced synergistic effects that provide an ideal metallic platform for much easier dehydrogenation of hydrocarbon molecules, more reasonable strength of adsorption energy of carbon monomer on surface and lower formation energies of carbon chains, largely renders the success growth of monolayer graphene with higher electrical mobility and lower defects. The growth mechanism is systemically investigated by our DFT calculations. This study provides a selective route for realizing high-quality graphene monolayer via a scalable synthetic method by using economic liquid carbon supplies and multialloy metal substrates.
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http://dx.doi.org/10.1021/acsnano.6b06144DOI Listing
February 2017

Metastatic Pancreatic Carcinoma and Experience with FOLFIRINOX - a Cross Sectional Analysis From a Developing Country.

Asian Pac J Cancer Prev 2015 ;16(14):6001-6

Department of Oncology, Fellow, Aga Khan University Hospital , Karachi, Pakistan E-mail :

Background: Pancreatic cancer is the fourth leading cause of cancer related death with median survival ranging from 3 to 6 months for metastatic disease. Palliative chemotherapy has been the backbone of treatment in advanced stage and has evolved over time. Data pertaining to the disease are scarce from our part of the world where treatment poses a significant challenge due to lack of resources.

Materials And Methods: A retrospective chart review was performed for all patients presenting with stage IV pancreatic carcinoma at a tertiary care hospital in Karachi, Pakistan between January 2008 and December 2012. Data were collected using a pre-designed, coded questionnaire looking at patient characteristics, treatment given and outcome.

Results: 101 patients were found to be eligible. Mean age was 56.7 ± 12.8 years, the male to female ratio was 2:1 and most patients had a good performance status. More than half of the tumors were located in the head (57%, n=58) and almost all were adenocarcinomas (95%, n=96). Some 58% (n=59) received first line chemotherapy of which 49% (n=29) received gemcitabine-based regimens and 39% (n=23) received FOLFIRINOX. The median progression free survival for gemcitabine based treatment was 2.9 months (IQR=1.6-5.6) as opposed to 7.3 months (IQR=4.5-9.2) for FOLFIRINOX (P=0.02). Median overall survival was 4.9 months (IQR=2.3-9.5) for first line gemcitabine based treatment and 10.5 months (IQR=7.0-13.2) for first line FOLFIRINOX therapy (P=0.002). Patients on FOLFIRINOX had better survival across all subgroups. Inpatient admissions and dose reductions were more frequent with FOLFIRINOX but the difference between the two regimens was not statistically significant. FOLFIRINOX could be successfully administered as outpatient therapy to a number of patients.

Conclusions: FOLFIRINOX remains a suitable first line option in patients with metastatic pancreatic cancer with good performance status even in a resource-poor country where diagnostic and supportive care facilities may be less than optimal and cost is a limitation.
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http://dx.doi.org/10.7314/apjcp.2015.16.14.6001DOI Listing
June 2016

t(1:14) and trisomy 4 in a patient with concomitant leukaemias.

J Pak Med Assoc 2014 May;64(5):596-8

Cytogenetic abnormalities have long been recognized as the genetic basis of the occurrence of various malignancies. Specific cytogenetic abnormalities have shown to occur recurrently in particular subtypes of leukaemias and lymphomas. t(1;14) is an infrequently occurring recurrent chromosomal translocation that has been described in literature to be associated with haematological malignancies. Trisomy 4 is another rare genetic abnormality which has been reported in association with both acute myeloid and lymphoid leukaemias. The concomitant occurrence of a myeloid malignancy in association with a lymphoproliferative disorder is a distinctly unusual phenomenon. We report the case of a young patient with concomitant T-cell acute lymphoblastic leukaemia and acute myeloid leukaemia with a novel cytogenetic abnormality i.e. t(1;14) with trisomy 4. We believe this is the first reported case where a patient with two concomitant haematological malignancies, harboured this karyotype.
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May 2014

Clinical features and outcome of sporadic colorectal carcinoma in young patients: a cross-sectional analysis from a developing country.

ISRN Oncol 2014 1;2014:461570. Epub 2014 Apr 1.

Department of Oncology, Aga Khan University Hospital, Stadium Road, P.O. Box 3500, Karachi 74800, Pakistan.

Background. Early onset colorectal carcinoma (CRC) is rare and has been hypothesized to be a biologically and clinically distinct entity personifying aggressive disease and worse survival. Methods. Data for 131 patients was collected by retrospective chart review. Cox proportional hazard model was used to compute prevalence ratios and 95% confidence intervals. Results. Early onset sporadic CRC accounted for 32% of all CRC treated in the specified time period. The mean age was 33.3 ± 7.9 years and the male to female ratio was 2 : 1. Colon and rectal cancers accounted for 55% and 45% of patients, respectively. 96% of rectal carcinoma patients received appropriate therapy as opposed to 65% of colon cancers. On multivariable analysis, appropriate reception of therapy (PR 4.99; 95% CI, 1.21-20.6) and signet ring morphology (PR 2.40; 95% CI, 1.33-4.32) were significantly associated with rectal cancers as opposed to colon cancer. Kaplan-Meier analysis revealed a trend towards inferior survival for rectal carcinoma 2 years after diagnosis. Conclusion.A high prevalence of early onset CRC was noted in the study. A trend towards inferior survival was seen in patients with rectal cancer. This finding raises the possibility of rectal carcinoma being an aggressive subset of young CRC.
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http://dx.doi.org/10.1155/2014/461570DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004039PMC
July 2014

Pleomorphic lobular carcinoma of the male breast with axillary lymph node involvement: a case report and review of literature.

BMC Clin Pathol 2014 27;14:16. Epub 2014 Apr 27.

Department of Oncology, Aga Khan University Hospital, Stadium Road, PO BOX: 3500, Karachi 74800, Pakistan.

Background: Carcinoma of the male breast is responsible for less than 1% of all malignancies in men but the incidence is rising. Invasive ductal carcinoma is the most common histological subtype while invasive lobular carcinoma is responsible for only 1.5% of the total cases of which pleomorpic lobular carcinoma is an extremely rare variant. We report the case of a gentleman with node positive, pleomorphic lobular carcinoma of the breast.

Case Presentation: An elderly gentleman with a past history of type 2 diabetes and long term ethanol use presented to us with a self-discovered palpable lump in the left breast. Physical examination revealed bilateral gynaecomastia along with a well circumscribed subareolar mass and palpable lymphadenopathy in the ipsilateral axilla. The breast nodule revealed atypical cells on fine needle aspiration biopsy and the patient underwent a modified radical mastectomy after systemic surveillance was negative for metastatic disease. The lesion was reported as grade III pleomorphic lobular carcinoma with a lack of E-cadherin expression on immunohistochemistry and the neoplastic cells exhibited strong positivity for estrogen receptor in the absence of Her2 gene amplification. Six out of the eleven dissected regional lymph nodes showed evidence of disease. The patient completed 4 cycles of adjuvant chemotherapy without evidence of recurrent disease and was subsequently lost to follow up.

Conclusions: Although invasive lobular carcinomas comprise 12% of all female breast cancers, they are very rare in males due to lack of acini and lobules in the normal male breast. Pleomorphic lobular carcinoma, an aggressive variant of ILC is even rarer in males. Chronic consumption of ethanol by our patient may have resulted in some degree of hepatic impairment with resultant hyperestrogenism. This in theory may have been the cause of his gynaecomastia, resultant breast cancer and is a plausible explanation for development of the invasive lobular subtype in a male. The prognosis and clinicopatholocial features of pleomorphic lobular carcinoma in men are less clearly defined due to its rarity. Additional studies are hence necessary to improve our understanding of this disease in males.
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http://dx.doi.org/10.1186/1472-6890-14-16DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008413PMC
May 2014

Ewing's sarcoma arising from the adrenal gland in a young male: a case report.

BMC Res Notes 2013 Dec 13;6:533. Epub 2013 Dec 13.

Department of Oncology, Aga Khan University Hospital, Stadium Road, PO BOX: 3500, Karachi 74800, Pakistan.

Background: Ewing's sarcoma uncommonly arises from extraosseous soft tissue or parenchymal organs. Primary adrenal Ewing's Sarcoma, although very rare, is extremely aggressive and commonly fatal.

Case Presentation: A 17 year old Pakistani male was referred to the outpatient oncology clinic at our center with a three month history of concomitant pain, swelling and dragging sensation in the right hypochondrium. Abdominal examination revealed a large, firm mass in the right hypochondrium extending into the right lumbar region and epigastrium. His genital exam was unremarkable and there were no stigmata of hepatic or adrenal disease.Computed tomography scans revealed a large peripherally enhancing mass in the hepatorenal area, biopsy of which showed a neoplastic lesion composed of small round blue cells which exhibited abundance of glycogen and stained diffusely positive for CD99 (MIC2 antigen). Fluorescence in situ hybridization demonstrated gene rearrangement at chromosome 22q12 which confirmed the diagnosis of Ewing's sarcoma. Staging scans revealed pulmonary metastasis and hence he was commenced on systemic chemotherapy.

Conclusion: This case report highlights the importance of keeping Ewing's sarcoma in mind when a young patient presents with a large non-functional adrenal mass.
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http://dx.doi.org/10.1186/1756-0500-6-533DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3867215PMC
December 2013

Cisplatin-induced posterior reversible encephalopathy syndrome and successful re-treatment in a patient with non-seminomatous germ cell tumor: a case report.

J Med Case Rep 2012 Nov 29;6:409. Epub 2012 Nov 29.

Department of Medicine, Division of Hematology and Oncology, Aga Khan University Hospital, Stadium Road, PO BOX: 3500, Karachi 74800, Pakistan.

Unlabelled:

Introduction: Cisplatin is a platinum compound that has revolutionized the treatment of various solid organ tumors. Cisplatin is associated with a variety of side effects and has recently been indicted in the development of posterior reversible encephalopathy syndrome. Posterior reversible encephalopathy syndrome is a potentially reversible condition, with the mainstay of therapy being correction of the underlying cause and withdrawal of the offending drug. However, there are no clear guidelines regarding the possibility of subsequent re-treatment with the causative agent.

Case Presentation: A 23-year-old Asian man presented to our Emergency Department with a four-month history of concomitant abdominal pain and backache and a two-week history of left-sided leg swelling. Diagnostic investigations revealed bilateral pulmonary embolism, extensive deep venous thrombosis and widespread lung and liver metastatic deposits with abdomino-pelvic lymphadenopathy. His biopsy and tumor markers were consistent with non-seminomatous germ cell tumor and he was subsequently started on an initial cycle of cisplatin and etoposide chemotherapy. On the second day of treatment he developed posterior reversible encephalopathy syndrome clinically and radiologically. Cisplatin was stopped for the next two days while etoposide was continued, resulting in complete resolution of his symptoms. He was re-challenged with cisplatin on day five of chemotherapy because a platin-based chemotherapy regimen was his only hope of potential cure. He tolerated it well, with no recurrence of his neurological symptoms and the remainder of his in-patient stay remained uneventful. He was discharged on day eight. He has since then completed treatment and is currently in remission.

Conclusions: The occurrence of posterior reversible encephalopathy syndrome after cisplatin use has been well reported in the literature. We strongly believe that our patient also developed posterior reversible encephalopathy syndrome secondary to cisplatin. The uniqueness of our patient's case lies in the successful re-treatment of our patient with the offending drug. To the best of our knowledge, this is the first instance where a patient was successfully re-treated with cisplatin after having developed posterior reversible encephalopathy syndrome as a result of cisplatin use. The excellent response to re-treatment without recurrence of neurological symptoms in our patient's case provides insight into re-treatment as an option in scenarios where treatment options are limited.
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http://dx.doi.org/10.1186/1752-1947-6-409DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3526411PMC
November 2012